diff --git a/frontend/src/hooks/tools/convert/useConvertOperation.ts b/frontend/src/hooks/tools/convert/useConvertOperation.ts
index 8d59641fe..4aaed74ee 100644
--- a/frontend/src/hooks/tools/convert/useConvertOperation.ts
+++ b/frontend/src/hooks/tools/convert/useConvertOperation.ts
@@ -1,5 +1,5 @@
 import { useCallback } from 'react';
-import axios from 'axios';
+import apiClient from '../../../services/apiClient';
 import { useTranslation } from 'react-i18next';
 import { ConvertParameters, defaultParameters } from './useConvertParameters';
 import { createFileFromApiResponse } from '../../../utils/fileResponseUtils';
@@ -108,7 +108,7 @@ export const convertProcessor = async (
     for (const file of selectedFiles) {
       try {
         const formData = buildConvertFormData(parameters, [file]);
-        const response = await axios.post(endpoint, formData, { responseType: 'blob' });
+        const response = await apiClient.post(endpoint, formData, { responseType: 'blob' });
 
         const convertedFile = createFileFromResponse(response.data, response.headers, file.name, parameters.toExtension);
 
@@ -120,7 +120,7 @@ export const convertProcessor = async (
   } else {
     // Batch processing for simple cases (image→PDF combine)
     const formData = buildConvertFormData(parameters, selectedFiles);
-    const response = await axios.post(endpoint, formData, { responseType: 'blob' });
+    const response = await apiClient.post(endpoint, formData, { responseType: 'blob' });
 
     const baseFilename = selectedFiles.length === 1
       ? selectedFiles[0].name
diff --git a/frontend/src/hooks/tools/shared/useToolApiCalls.ts b/frontend/src/hooks/tools/shared/useToolApiCalls.ts
index f0a0bf704..5747ec226 100644
--- a/frontend/src/hooks/tools/shared/useToolApiCalls.ts
+++ b/frontend/src/hooks/tools/shared/useToolApiCalls.ts
@@ -1,5 +1,6 @@
 import { useCallback, useRef } from 'react';
-import axios, { CancelTokenSource } from '../../../services/http';
+import axios, {type CancelTokenSource} from 'axios'; // Real axios for static methods (CancelToken, isCancel)
+import apiClient from '../../../services/apiClient'; // Our configured instance
 import { processResponse, ResponseHandler } from '../../../utils/toolResponseProcessor';
 import { isEmptyOutput } from '../../../services/errorUtils';
 import type { ProcessingProgress } from './useToolState';
@@ -42,9 +43,9 @@ export const useToolApiCalls = <TParams = void>() => {
         const formData = config.buildFormData(params, file);
         const endpoint = typeof config.endpoint === 'function' ? config.endpoint(params) : config.endpoint;
         console.debug('[processFiles] POST', { endpoint, name: file.name });
-        const response = await axios.post(endpoint, formData, {
+        const response = await apiClient.post(endpoint, formData, {
           responseType: 'blob',
-          cancelToken: cancelTokenRef.current.token,
+          cancelToken: cancelTokenRef.current?.token,
         });
         console.debug('[processFiles] Response OK', { name: file.name, status: (response as any)?.status });
 
@@ -61,10 +62,10 @@ export const useToolApiCalls = <TParams = void>() => {
         if (empty) {
           console.warn('[processFiles] Empty output treated as failure', { name: file.name });
           failedFiles.push(file.name);
-          try { 
-            (markFileError as any)?.((file as any).fileId); 
-          } catch (e) { 
-            console.debug('markFileError', e); 
+          try {
+            (markFileError as any)?.((file as any).fileId);
+          } catch (e) {
+            console.debug('markFileError', e);
           }
           continue;
         }
@@ -80,10 +81,10 @@ export const useToolApiCalls = <TParams = void>() => {
         console.error('[processFiles] Failed', { name: file.name, error });
         failedFiles.push(file.name);
         // mark errored file so UI can highlight
-        try { 
-          (markFileError as any)?.((file as any).fileId); 
-        } catch (e) { 
-          console.debug('markFileError', e); 
+        try {
+          (markFileError as any)?.((file as any).fileId);
+        } catch (e) {
+          console.debug('markFileError', e);
         }
       }
     }
diff --git a/frontend/src/hooks/tools/shared/useToolOperation.ts b/frontend/src/hooks/tools/shared/useToolOperation.ts
index 2e9c67bd3..91b3c8d0c 100644
--- a/frontend/src/hooks/tools/shared/useToolOperation.ts
+++ b/frontend/src/hooks/tools/shared/useToolOperation.ts
@@ -1,5 +1,5 @@
 import { useCallback, useRef, useEffect } from 'react';
-import axios from '../../../services/http';
+import apiClient from '../../../services/apiClient';
 import { useTranslation } from 'react-i18next';
 import { useFileContext } from '../../../contexts/FileContext';
 import { useToolState, type ProcessingProgress } from './useToolState';
@@ -177,8 +177,8 @@ export const useToolOperation = <TParams>(
         for (const f of zeroByteFiles) {
           (fileActions.markFileError as any)((f as any).fileId);
         }
-      } catch (e) { 
-        console.log('markFileError', e); 
+      } catch (e) {
+        console.log('markFileError', e);
       }
     }
     const validFiles = selectedFiles.filter(file => (file as any)?.size > 0);
@@ -243,7 +243,7 @@ export const useToolOperation = <TParams>(
           const formData = config.buildFormData(params, filesForAPI);
           const endpoint = typeof config.endpoint === 'function' ? config.endpoint(params) : config.endpoint;
 
-          const response = await axios.post(endpoint, formData, { responseType: 'blob' });
+          const response = await apiClient.post(endpoint, formData, { responseType: 'blob' });
 
           // Multi-file responses are typically ZIP files that need extraction, but some may return single PDFs
           if (config.responseHandler) {
diff --git a/frontend/src/services/apiClient.ts b/frontend/src/services/apiClient.ts
new file mode 100644
index 000000000..536c47448
--- /dev/null
+++ b/frontend/src/services/apiClient.ts
@@ -0,0 +1,22 @@
+// frontend/src/services/http.ts
+import axios from 'axios';
+import { handleHttpError } from './httpErrorHandler';
+
+// Create axios instance with default config
+const apiClient = axios.create({
+  baseURL: import.meta.env.VITE_API_BASE_URL || '/', // Use env var or relative path (proxied by Vite in dev)
+  responseType: 'json',
+});
+
+// ---------- Install error interceptor ----------
+apiClient.interceptors.response.use(
+  (response) => response,
+  async (error) => {
+    await handleHttpError(error); // Handle error (shows toast unless suppressed)
+    return Promise.reject(error);
+  }
+);
+
+
+// ---------- Exports ----------
+export default apiClient;
diff --git a/frontend/src/services/http.ts b/frontend/src/services/http.ts
deleted file mode 100644
index 20a983525..000000000
--- a/frontend/src/services/http.ts
+++ /dev/null
@@ -1,255 +0,0 @@
-// frontend/src/services/http.ts
-import axios from 'axios';
-import type { AxiosInstance } from 'axios';
-import { alert } from '../components/toast';
-import { broadcastErroredFiles, extractErrorFileIds, normalizeAxiosErrorData } from './errorUtils';
-import { showSpecialErrorToast } from './specialErrorToasts';
-
-const FRIENDLY_FALLBACK = 'There was an error processing your request.';
-const MAX_TOAST_BODY_CHARS = 400; // avoid massive, unreadable toasts
-
-function clampText(s: string, max = MAX_TOAST_BODY_CHARS): string {
-  return s && s.length > max ? `${s.slice(0, max)}…` : s;
-}
-
-function isUnhelpfulMessage(msg: string | null | undefined): boolean {
-  const s = (msg || '').trim();
-  if (!s) return true;
-  // Common unhelpful payloads we see
-  if (s === '{}' || s === '[]') return true;
-  if (/^request failed/i.test(s)) return true;
-  if (/^network error/i.test(s)) return true;
-  if (/^[45]\d\d\b/.test(s)) return true; // "500 Server Error" etc.
-  return false;
-}
-
-function titleForStatus(status?: number): string {
-  if (!status) return 'Network error';
-  if (status >= 500) return 'Server error';
-  if (status >= 400) return 'Request error';
-  return 'Request failed';
-}
-
-function extractAxiosErrorMessage(error: any): { title: string; body: string } {
-  if (axios.isAxiosError(error)) {
-    const status = error.response?.status;
-    const _statusText = error.response?.statusText || '';
-    let parsed: any = undefined;
-    const raw = error.response?.data;
-    if (typeof raw === 'string') {
-      try { parsed = JSON.parse(raw); } catch { /* keep as string */ }
-    } else {
-      parsed = raw;
-    }
-    const extractIds = (): string[] | undefined => {
-      if (Array.isArray(parsed?.errorFileIds)) return parsed.errorFileIds as string[];
-      const rawText = typeof raw === 'string' ? raw : '';
-      const uuidMatches = rawText.match(/[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}/g);
-      return uuidMatches && uuidMatches.length > 0 ? Array.from(new Set(uuidMatches)) : undefined;
-    };
-
-    const body = ((): string => {
-      const data = parsed;
-      if (!data) return typeof raw === 'string' ? raw : '';
-      const ids = extractIds();
-      if (ids && ids.length > 0) return `Failed files: ${ids.join(', ')}`;
-      if (data?.message) return data.message as string;
-      if (typeof raw === 'string') return raw;
-      try { return JSON.stringify(data); } catch { return ''; }
-    })();
-    const ids = extractIds();
-    const title = titleForStatus(status);
-    if (ids && ids.length > 0) {
-      return { title, body: 'Process failed due to invalid/corrupted file(s)' };
-    }
-    if (status === 422) {
-      const fallbackMsg = 'Process failed due to invalid/corrupted file(s)';
-      const bodyMsg = isUnhelpfulMessage(body) ? fallbackMsg : body;
-      return { title, body: bodyMsg };
-    }
-    const bodyMsg = isUnhelpfulMessage(body) ? FRIENDLY_FALLBACK : body;
-    return { title, body: bodyMsg };
-  }
-  try {
-    const msg = (error?.message || String(error)) as string;
-    return { title: 'Network error', body: isUnhelpfulMessage(msg) ? FRIENDLY_FALLBACK : msg };
-  } catch (e) {
-    // ignore extraction errors
-    console.debug('extractAxiosErrorMessage', e);
-    return { title: 'Network error', body: FRIENDLY_FALLBACK };
-  }
-}
-
-// ---------- Axios instance creation ----------
-const __globalAny = (typeof window !== 'undefined' ? (window as any) : undefined);
-
-type ExtendedAxiosInstance = AxiosInstance & {
-  CancelToken: typeof axios.CancelToken;
-  isCancel: typeof axios.isCancel;
-};
-
-const __PREV_CLIENT: ExtendedAxiosInstance | undefined =
-  __globalAny?.__SPDF_HTTP_CLIENT as ExtendedAxiosInstance | undefined;
-
-let __createdClient: any;
-if (__PREV_CLIENT) {
-  __createdClient = __PREV_CLIENT;
-} else if (typeof (axios as any)?.create === 'function') {
-  try {
-    __createdClient = (axios as any).create();
-  } catch (e) {
-    console.debug('createClient', e);
-    __createdClient = axios as any;
-  }
-} else {
-  __createdClient = axios as any;
-}
-
-const apiClient: ExtendedAxiosInstance = (__createdClient || (axios as any)) as ExtendedAxiosInstance;
-
-// Augment instance with axios static helpers for backwards compatibility 
-if (apiClient) {
-  try { (apiClient as any).CancelToken = (axios as any).CancelToken; } catch (e) { console.debug('setCancelToken', e); }
-  try { (apiClient as any).isCancel = (axios as any).isCancel; } catch (e) { console.debug('setIsCancel', e); }
-}
-
-// ---------- Base defaults  ----------
-try {
-  const env = (import.meta as any)?.env || {};
-  apiClient.defaults.baseURL = env?.VITE_API_BASE_URL ?? '/';
-  apiClient.defaults.responseType = 'json';
-  // If OSS relies on cookies, uncomment:
-  // apiClient.defaults.withCredentials = true;
-  // Sensible timeout to avoid “forever hanging”:
-  apiClient.defaults.timeout = 20000;
-} catch (e) {
-  console.debug('setDefaults', e);
-  apiClient.defaults.baseURL = apiClient.defaults.baseURL || '/';
-  apiClient.defaults.responseType = apiClient.defaults.responseType || 'json';
-  apiClient.defaults.timeout = apiClient.defaults.timeout || 20000;
-}
-
-// ---------- Install a single response error interceptor (dedup + UX) ----------
-if (__globalAny?.__SPDF_HTTP_ERR_INTERCEPTOR_ID !== undefined && __PREV_CLIENT) {
-  try {
-    __PREV_CLIENT.interceptors.response.eject(__globalAny.__SPDF_HTTP_ERR_INTERCEPTOR_ID);
-  } catch (e) {
-    console.debug('ejectInterceptor', e);
-  }
-}
-
-const __recentSpecialByEndpoint: Record<string, number> = (__globalAny?.__SPDF_RECENT_SPECIAL || {});
-const __SPECIAL_SUPPRESS_MS = 1500; // brief window to suppress generic duplicate after special toast
-
-const __INTERCEPTOR_ID__ = apiClient?.interceptors?.response?.use
-  ? apiClient.interceptors.response.use(
-    (response) => response,
-    async (error) => {
-      // Compute title/body (friendly) from the error object
-      const { title, body } = extractAxiosErrorMessage(error);
-
-      // Normalize response data ONCE, reuse for both ID extraction and special-toast matching
-      const raw = (error?.response?.data) as any;
-      let normalized: unknown = raw;
-      try { normalized = await normalizeAxiosErrorData(raw); } catch (e) { console.debug('normalizeAxiosErrorData', e); }
-
-      // 1) If server sends structured file IDs for failures, also mark them errored in UI
-      try {
-        const ids = extractErrorFileIds(normalized);
-        if (ids && ids.length > 0) {
-          broadcastErroredFiles(ids);
-        }
-      } catch (e) {
-        console.debug('extractErrorFileIds', e);
-      }
-
-      // 2) Generic-vs-special dedupe by endpoint
-      const url: string | undefined = error?.config?.url;
-      const status: number | undefined = error?.response?.status;
-      const now = Date.now();
-      const isSpecial =
-        status === 422 ||
-        status === 409 || // often actionable conflicts
-        /Failed files:/.test(body) ||
-        /invalid\/corrupted file\(s\)/i.test(body);
-
-      if (isSpecial && url) {
-        __recentSpecialByEndpoint[url] = now;
-        if (__globalAny) __globalAny.__SPDF_RECENT_SPECIAL = __recentSpecialByEndpoint;
-      }
-      if (!isSpecial && url) {
-        const last = __recentSpecialByEndpoint[url] || 0;
-        if (now - last < __SPECIAL_SUPPRESS_MS) {
-          return Promise.reject(error);
-        }
-      }
-
-      // 3) Show specialized friendly toasts if matched; otherwise show the generic one
-      let rawString: string | undefined;
-      try {
-        rawString =
-          typeof normalized === 'string'
-            ? normalized
-            : JSON.stringify(normalized);
-      } catch (e) {
-        console.debug('extractErrorFileIds', e);
-      }
-
-      const handled = showSpecialErrorToast(rawString, { status });
-      if (!handled) {
-        const displayBody = clampText(body);
-        alert({ alertType: 'error', title, body: displayBody, expandable: true, isPersistentPopup: false });
-      }
-
-      return Promise.reject(error);
-    }
-  )
-  : undefined as any;
-
-if (__globalAny) {
-  __globalAny.__SPDF_HTTP_ERR_INTERCEPTOR_ID = __INTERCEPTOR_ID__;
-  __globalAny.__SPDF_RECENT_SPECIAL = __recentSpecialByEndpoint;
-  __globalAny.__SPDF_HTTP_CLIENT = apiClient;
-}
-
-// ---------- Fetch helper ----------
-export async function apiFetch(input: RequestInfo | URL, init?: RequestInit): Promise<Response> {
-  const res = await fetch(input, { credentials: init?.credentials ?? 'include', ...init });
-
-  if (!res.ok) {
-    let detail = '';
-    try {
-      const ct = res.headers.get('content-type') || '';
-      if (ct.includes('application/json')) {
-        const data = await res.json();
-        detail = typeof data === 'string' ? data : (data?.message || JSON.stringify(data));
-      } else {
-        detail = await res.text();
-      }
-    } catch {
-      // ignore parse errors
-    }
-
-    const title = titleForStatus(res.status);
-    const body = isUnhelpfulMessage(detail || res.statusText) ? FRIENDLY_FALLBACK : (detail || res.statusText);
-    alert({ alertType: 'error', title, body: clampText(body), expandable: true, isPersistentPopup: false });
-
-    // Important: match Axios semantics so callers can try/catch
-    throw new Error(body || res.statusText);
-  }
-
-  return res;
-}
-
-// ---------- Convenience API surface and exports ----------
-export const api = {
-  get: apiClient.get,
-  post: apiClient.post,
-  put: apiClient.put,
-  patch: apiClient.patch,
-  delete: apiClient.delete,
-  request: apiClient.request,
-};
-
-export default apiClient;
-export type { CancelTokenSource } from 'axios';
\ No newline at end of file
diff --git a/frontend/src/services/httpErrorHandler.ts b/frontend/src/services/httpErrorHandler.ts
new file mode 100644
index 000000000..aaea20036
--- /dev/null
+++ b/frontend/src/services/httpErrorHandler.ts
@@ -0,0 +1,147 @@
+// frontend/src/services/httpErrorHandler.ts
+import axios from 'axios';
+import { alert } from '../components/toast';
+import { broadcastErroredFiles, extractErrorFileIds, normalizeAxiosErrorData } from './errorUtils';
+import { showSpecialErrorToast } from './specialErrorToasts';
+
+const FRIENDLY_FALLBACK = 'There was an error processing your request.';
+const MAX_TOAST_BODY_CHARS = 400; // avoid massive, unreadable toasts
+
+function clampText(s: string, max = MAX_TOAST_BODY_CHARS): string {
+  return s && s.length > max ? `${s.slice(0, max)}…` : s;
+}
+
+function isUnhelpfulMessage(msg: string | null | undefined): boolean {
+  const s = (msg || '').trim();
+  if (!s) return true;
+  // Common unhelpful payloads we see
+  if (s === '{}' || s === '[]') return true;
+  if (/^request failed/i.test(s)) return true;
+  if (/^network error/i.test(s)) return true;
+  if (/^[45]\d\d\b/.test(s)) return true; // "500 Server Error" etc.
+  return false;
+}
+
+function titleForStatus(status?: number): string {
+  if (!status) return 'Network error';
+  if (status >= 500) return 'Server error';
+  if (status >= 400) return 'Request error';
+  return 'Request failed';
+}
+
+function extractAxiosErrorMessage(error: any): { title: string; body: string } {
+  if (axios.isAxiosError(error)) {
+    const status = error.response?.status;
+    const _statusText = error.response?.statusText || '';
+    let parsed: any = undefined;
+    const raw = error.response?.data;
+    if (typeof raw === 'string') {
+      try { parsed = JSON.parse(raw); } catch { /* keep as string */ }
+    } else {
+      parsed = raw;
+    }
+    const extractIds = (): string[] | undefined => {
+      if (Array.isArray(parsed?.errorFileIds)) return parsed.errorFileIds as string[];
+      const rawText = typeof raw === 'string' ? raw : '';
+      const uuidMatches = rawText.match(/[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}/g);
+      return uuidMatches && uuidMatches.length > 0 ? Array.from(new Set(uuidMatches)) : undefined;
+    };
+
+    const body = ((): string => {
+      const data = parsed;
+      if (!data) return typeof raw === 'string' ? raw : '';
+      const ids = extractIds();
+      if (ids && ids.length > 0) return `Failed files: ${ids.join(', ')}`;
+      if (data?.message) return data.message as string;
+      if (typeof raw === 'string') return raw;
+      try { return JSON.stringify(data); } catch { return ''; }
+    })();
+    const ids = extractIds();
+    const title = titleForStatus(status);
+    if (ids && ids.length > 0) {
+      return { title, body: 'Process failed due to invalid/corrupted file(s)' };
+    }
+    if (status === 422) {
+      const fallbackMsg = 'Process failed due to invalid/corrupted file(s)';
+      const bodyMsg = isUnhelpfulMessage(body) ? fallbackMsg : body;
+      return { title, body: bodyMsg };
+    }
+    const bodyMsg = isUnhelpfulMessage(body) ? FRIENDLY_FALLBACK : body;
+    return { title, body: bodyMsg };
+  }
+  try {
+    const msg = (error?.message || String(error)) as string;
+    return { title: 'Network error', body: isUnhelpfulMessage(msg) ? FRIENDLY_FALLBACK : msg };
+  } catch (e) {
+    // ignore extraction errors
+    console.debug('extractAxiosErrorMessage', e);
+    return { title: 'Network error', body: FRIENDLY_FALLBACK };
+  }
+}
+
+// Module-scoped state to reduce global variable usage
+const recentSpecialByEndpoint: Record<string, number> = {};
+const SPECIAL_SUPPRESS_MS = 1500; // brief window to suppress generic duplicate after special toast
+
+/**
+ * Handles HTTP errors with toast notifications and file error broadcasting
+ * Returns true if the error should be suppressed (deduplicated), false otherwise
+ */
+export async function handleHttpError(error: any): Promise<boolean> {
+  // Compute title/body (friendly) from the error object
+  const { title, body } = extractAxiosErrorMessage(error);
+
+  // Normalize response data ONCE, reuse for both ID extraction and special-toast matching
+  const raw = (error?.response?.data) as any;
+  let normalized: unknown = raw;
+  try { normalized = await normalizeAxiosErrorData(raw); } catch (e) { console.debug('normalizeAxiosErrorData', e); }
+
+  // 1) If server sends structured file IDs for failures, also mark them errored in UI
+  try {
+    const ids = extractErrorFileIds(normalized);
+    if (ids && ids.length > 0) {
+      broadcastErroredFiles(ids);
+    }
+  } catch (e) {
+    console.debug('extractErrorFileIds', e);
+  }
+
+  // 2) Generic-vs-special dedupe by endpoint
+  const url: string | undefined = error?.config?.url;
+  const status: number | undefined = error?.response?.status;
+  const now = Date.now();
+  const isSpecial =
+    status === 422 ||
+    status === 409 || // often actionable conflicts
+    /Failed files:/.test(body) ||
+    /invalid\/corrupted file\(s\)/i.test(body);
+
+  if (isSpecial && url) {
+    recentSpecialByEndpoint[url] = now;
+  }
+  if (!isSpecial && url) {
+    const last = recentSpecialByEndpoint[url] || 0;
+    if (now - last < SPECIAL_SUPPRESS_MS) {
+      return true; // Suppress this error (deduplicated)
+    }
+  }
+
+  // 3) Show specialized friendly toasts if matched; otherwise show the generic one
+  let rawString: string | undefined;
+  try {
+    rawString =
+      typeof normalized === 'string'
+        ? normalized
+        : JSON.stringify(normalized);
+  } catch (e) {
+    console.debug('extractErrorFileIds', e);
+  }
+
+  const handled = showSpecialErrorToast(rawString, { status });
+  if (!handled) {
+    const displayBody = clampText(body);
+    alert({ alertType: 'error', title, body: displayBody, expandable: true, isPersistentPopup: false });
+  }
+
+  return false; // Error was handled with toast, continue normal rejection
+}
\ No newline at end of file
diff --git a/frontend/src/tests/convert/ConvertIntegration.test.tsx b/frontend/src/tests/convert/ConvertIntegration.test.tsx
index 2d3e177c6..c2398dab7 100644
--- a/frontend/src/tests/convert/ConvertIntegration.test.tsx
+++ b/frontend/src/tests/convert/ConvertIntegration.test.tsx
@@ -17,13 +17,40 @@ import { ConvertParameters } from '../../hooks/tools/convert/useConvertParameter
 import { FileContextProvider } from '../../contexts/FileContext';
 import { I18nextProvider } from 'react-i18next';
 import i18n from '../../i18n/config';
-import axios from 'axios';
 import { createTestStirlingFile } from '../utils/testFileHelpers';
 import { StirlingFile } from '../../types/fileContext';
 
-// Mock axios
-vi.mock('axios');
-const mockedAxios = vi.mocked(axios);
+// Mock axios (for static methods like CancelToken, isCancel)
+vi.mock('axios', () => ({
+  default: {
+    CancelToken: {
+      source: vi.fn(() => ({
+        token: 'mock-cancel-token',
+        cancel: vi.fn()
+      }))
+    },
+    isCancel: vi.fn(() => false),
+  }
+}));
+
+// Mock our apiClient service
+vi.mock('../../services/apiClient', () => ({
+  default: {
+    post: vi.fn(),
+    get: vi.fn(),
+    put: vi.fn(),
+    delete: vi.fn(),
+    interceptors: {
+      response: {
+        use: vi.fn()
+      }
+    }
+  }
+}));
+
+// Import the mocked apiClient
+import apiClient from '../../services/apiClient';
+const mockedApiClient = vi.mocked(apiClient);
 
 // Mock only essential services that are actually called by the tests
 vi.mock('../../services/fileStorage', () => ({
@@ -71,8 +98,8 @@ describe('Convert Tool Integration Tests', () => {
 
   beforeEach(() => {
     vi.clearAllMocks();
-    // Setup default axios mock
-    mockedAxios.post = vi.fn();
+    // Setup default apiClient mock
+    mockedApiClient.post = vi.fn();
   });
 
   afterEach(() => {
@@ -83,7 +110,7 @@ describe('Convert Tool Integration Tests', () => {
 
     test('should make correct API call for PDF to PNG conversion', async () => {
       const mockBlob = new Blob(['fake-image-data'], { type: 'image/png' });
-      (mockedAxios.post as Mock).mockResolvedValueOnce({
+      (mockedApiClient.post as Mock).mockResolvedValueOnce({
         data: mockBlob,
         status: 200,
         statusText: 'OK'
@@ -126,14 +153,14 @@ describe('Convert Tool Integration Tests', () => {
       });
 
       // Verify axios was called with correct parameters
-      expect(mockedAxios.post).toHaveBeenCalledWith(
+      expect(mockedApiClient.post).toHaveBeenCalledWith(
         '/api/v1/convert/pdf/img',
         expect.any(FormData),
         { responseType: 'blob' }
       );
 
       // Verify FormData contains correct parameters
-      const formDataCall = (mockedAxios.post as Mock).mock.calls[0][1] as FormData;
+      const formDataCall = (mockedApiClient.post as Mock).mock.calls[0][1] as FormData;
       expect(formDataCall.get('imageFormat')).toBe('png');
       expect(formDataCall.get('colorType')).toBe('color');
       expect(formDataCall.get('dpi')).toBe('300');
@@ -148,7 +175,7 @@ describe('Convert Tool Integration Tests', () => {
 
     test('should handle API error responses correctly', async () => {
       const errorMessage = 'Invalid file format';
-      (mockedAxios.post as Mock).mockRejectedValueOnce({
+      (mockedApiClient.post as Mock).mockRejectedValueOnce({
         response: {
           status: 400,
           data: errorMessage
@@ -199,7 +226,7 @@ describe('Convert Tool Integration Tests', () => {
     });
 
     test('should handle network errors gracefully', async () => {
-      (mockedAxios.post as Mock).mockRejectedValueOnce(new Error('Network error'));
+      (mockedApiClient.post as Mock).mockRejectedValueOnce(new Error('Network error'));
 
       const { result } = renderHook(() => useConvertOperation(), {
         wrapper: TestWrapper
@@ -246,7 +273,7 @@ describe('Convert Tool Integration Tests', () => {
 
     test('should correctly map image conversion parameters to API call', async () => {
       const mockBlob = new Blob(['fake-data'], { type: 'image/jpeg' });
-      (mockedAxios.post as Mock).mockResolvedValueOnce({
+      (mockedApiClient.post as Mock).mockResolvedValueOnce({
         data: mockBlob,
         status: 200,
         headers: {
@@ -292,7 +319,7 @@ describe('Convert Tool Integration Tests', () => {
       });
 
       // Verify integration: hook parameters → FormData → axios call → hook state
-      const formDataCall = (mockedAxios.post as Mock).mock.calls[0][1] as FormData;
+      const formDataCall = (mockedApiClient.post as Mock).mock.calls[0][1] as FormData;
       expect(formDataCall.get('imageFormat')).toBe('jpg');
       expect(formDataCall.get('colorType')).toBe('grayscale');
       expect(formDataCall.get('dpi')).toBe('150');
@@ -307,7 +334,7 @@ describe('Convert Tool Integration Tests', () => {
 
     test('should make correct API call for PDF to CSV conversion with simplified workflow', async () => {
       const mockBlob = new Blob(['fake-csv-data'], { type: 'text/csv' });
-      (mockedAxios.post as Mock).mockResolvedValueOnce({
+      (mockedApiClient.post as Mock).mockResolvedValueOnce({
         data: mockBlob,
         status: 200,
         statusText: 'OK'
@@ -350,14 +377,14 @@ describe('Convert Tool Integration Tests', () => {
       });
 
       // Verify correct endpoint is called
-      expect(mockedAxios.post).toHaveBeenCalledWith(
+      expect(mockedApiClient.post).toHaveBeenCalledWith(
         '/api/v1/convert/pdf/csv',
         expect.any(FormData),
         { responseType: 'blob' }
       );
 
       // Verify FormData contains correct parameters for simplified CSV conversion
-      const formDataCall = (mockedAxios.post as Mock).mock.calls[0][1] as FormData;
+      const formDataCall = (mockedApiClient.post as Mock).mock.calls[0][1] as FormData;
       expect(formDataCall.get('pageNumbers')).toBe('all'); // Always "all" for simplified workflow
       expect(formDataCall.get('fileInput')).toBe(testFile);
 
@@ -406,7 +433,7 @@ describe('Convert Tool Integration Tests', () => {
       });
 
       // Verify integration: utils validation prevents API call, hook shows error
-      expect(mockedAxios.post).not.toHaveBeenCalled();
+      expect(mockedApiClient.post).not.toHaveBeenCalled();
       expect(result.current.errorMessage).toContain('Unsupported conversion format');
       expect(result.current.isLoading).toBe(false);
       expect(result.current.downloadUrl).toBe(null);
@@ -417,7 +444,7 @@ describe('Convert Tool Integration Tests', () => {
 
     test('should handle multiple file uploads correctly', async () => {
       const mockBlob = new Blob(['zip-content'], { type: 'application/zip' });
-      (mockedAxios.post as Mock).mockResolvedValueOnce({ data: mockBlob });
+      (mockedApiClient.post as Mock).mockResolvedValueOnce({ data: mockBlob });
 
       const { result } = renderHook(() => useConvertOperation(), {
         wrapper: TestWrapper
@@ -458,7 +485,7 @@ describe('Convert Tool Integration Tests', () => {
       });
 
       // Verify both files were uploaded
-      const calls = (mockedAxios.post as Mock).mock.calls;
+      const calls = (mockedApiClient.post as Mock).mock.calls;
 
       for (let i = 0; i < calls.length; i++) {
         const formData = calls[i][1] as FormData;
@@ -506,7 +533,7 @@ describe('Convert Tool Integration Tests', () => {
         await result.current.executeOperation(parameters, []);
       });
 
-      expect(mockedAxios.post).not.toHaveBeenCalled();
+      expect(mockedApiClient.post).not.toHaveBeenCalled();
       expect(result.current.errorMessage).toContain('noFileSelected');
     });
   });
@@ -514,7 +541,7 @@ describe('Convert Tool Integration Tests', () => {
   describe('Error Boundary Integration', () => {
 
     test('should handle corrupted file gracefully', async () => {
-      (mockedAxios.post as Mock).mockRejectedValueOnce({
+      (mockedApiClient.post as Mock).mockRejectedValueOnce({
         response: {
           status: 422,
           data: 'Processing failed'
@@ -562,7 +589,7 @@ describe('Convert Tool Integration Tests', () => {
     });
 
     test('should handle backend service unavailable', async () => {
-      (mockedAxios.post as Mock).mockRejectedValueOnce({
+      (mockedApiClient.post as Mock).mockRejectedValueOnce({
         response: {
           status: 503,
           data: 'Service unavailable'
@@ -614,7 +641,7 @@ describe('Convert Tool Integration Tests', () => {
 
     test('should record operation in FileContext', async () => {
       const mockBlob = new Blob(['fake-data'], { type: 'image/png' });
-      (mockedAxios.post as Mock).mockResolvedValueOnce({
+      (mockedApiClient.post as Mock).mockResolvedValueOnce({
         data: mockBlob,
         status: 200,
         headers: {
@@ -667,7 +694,7 @@ describe('Convert Tool Integration Tests', () => {
 
     test('should clean up blob URLs on reset', async () => {
       const mockBlob = new Blob(['fake-data'], { type: 'image/png' });
-      (mockedAxios.post as Mock).mockResolvedValueOnce({
+      (mockedApiClient.post as Mock).mockResolvedValueOnce({
         data: mockBlob,
         status: 200,
         headers: {
diff --git a/frontend/src/tests/convert/ConvertSmartDetectionIntegration.test.tsx b/frontend/src/tests/convert/ConvertSmartDetectionIntegration.test.tsx
index 52826ce3f..cf28da955 100644
--- a/frontend/src/tests/convert/ConvertSmartDetectionIntegration.test.tsx
+++ b/frontend/src/tests/convert/ConvertSmartDetectionIntegration.test.tsx
@@ -11,14 +11,41 @@ import { useConvertParameters } from '../../hooks/tools/convert/useConvertParame
 import { FileContextProvider } from '../../contexts/FileContext';
 import { I18nextProvider } from 'react-i18next';
 import i18n from '../../i18n/config';
-import axios from 'axios';
 import { detectFileExtension } from '../../utils/fileUtils';
 import { FIT_OPTIONS } from '../../constants/convertConstants';
 import { createTestStirlingFile, createTestFilesWithId } from '../utils/testFileHelpers';
 
-// Mock axios
-vi.mock('axios');
-const mockedAxios = vi.mocked(axios);
+// Mock axios (for static methods like CancelToken, isCancel)
+vi.mock('axios', () => ({
+  default: {
+    CancelToken: {
+      source: vi.fn(() => ({
+        token: 'mock-cancel-token',
+        cancel: vi.fn()
+      }))
+    },
+    isCancel: vi.fn(() => false),
+  }
+}));
+
+// Mock our apiClient service
+vi.mock('../../services/apiClient', () => ({
+  default: {
+    post: vi.fn(),
+    get: vi.fn(),
+    put: vi.fn(),
+    delete: vi.fn(),
+    interceptors: {
+      response: {
+        use: vi.fn()
+      }
+    }
+  }
+}));
+
+// Import the mocked apiClient
+import apiClient from '../../services/apiClient';
+const mockedApiClient = vi.mocked(apiClient);
 
 // Mock only essential services that are actually called by the tests
 vi.mock('../../services/fileStorage', () => ({
@@ -61,7 +88,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
     vi.clearAllMocks();
 
     // Mock successful API response
-    (mockedAxios.post as Mock).mockResolvedValue({
+    (mockedApiClient.post as Mock).mockResolvedValue({
       data: new Blob(['fake converted content'], { type: 'application/pdf' })
     });
   });
@@ -103,7 +130,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         );
       });
 
-      expect(mockedAxios.post).toHaveBeenCalledWith('/api/v1/convert/file/pdf', expect.any(FormData), {
+      expect(mockedApiClient.post).toHaveBeenCalledWith('/api/v1/convert/file/pdf', expect.any(FormData), {
         responseType: 'blob'
       });
     });
@@ -139,7 +166,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         );
       });
 
-      expect(mockedAxios.post).toHaveBeenCalledWith('/api/v1/convert/file/pdf', expect.any(FormData), {
+      expect(mockedApiClient.post).toHaveBeenCalledWith('/api/v1/convert/file/pdf', expect.any(FormData), {
         responseType: 'blob'
       });
     });
@@ -183,12 +210,12 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         );
       });
 
-      expect(mockedAxios.post).toHaveBeenCalledWith('/api/v1/convert/img/pdf', expect.any(FormData), {
+      expect(mockedApiClient.post).toHaveBeenCalledWith('/api/v1/convert/img/pdf', expect.any(FormData), {
         responseType: 'blob'
       });
 
       // Should send all files in single request
-      const formData = (mockedAxios.post as Mock).mock.calls[0][1] as FormData;
+      const formData = (mockedApiClient.post as Mock).mock.calls[0][1] as FormData;
       const files = formData.getAll('fileInput');
       expect(files).toHaveLength(3);
     });
@@ -229,7 +256,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         );
       });
 
-      expect(mockedAxios.post).toHaveBeenCalledWith('/api/v1/convert/file/pdf', expect.any(FormData), {
+      expect(mockedApiClient.post).toHaveBeenCalledWith('/api/v1/convert/file/pdf', expect.any(FormData), {
         responseType: 'blob'
       });
     });
@@ -269,12 +296,12 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         );
       });
 
-      expect(mockedAxios.post).toHaveBeenCalledWith('/api/v1/convert/html/pdf', expect.any(FormData), {
+      expect(mockedApiClient.post).toHaveBeenCalledWith('/api/v1/convert/html/pdf', expect.any(FormData), {
         responseType: 'blob'
       });
 
       // Should process files separately for web files
-      expect(mockedAxios.post).toHaveBeenCalledTimes(2);
+      expect(mockedApiClient.post).toHaveBeenCalledTimes(2);
     });
   });
 
@@ -306,7 +333,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         );
       });
 
-      const formData = (mockedAxios.post as Mock).mock.calls[0][1] as FormData;
+      const formData = (mockedApiClient.post as Mock).mock.calls[0][1] as FormData;
       expect(formData.get('zoom')).toBe('1.5');
     });
 
@@ -340,7 +367,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         );
       });
 
-      const formData = (mockedAxios.post as Mock).mock.calls[0][1] as FormData;
+      const formData = (mockedApiClient.post as Mock).mock.calls[0][1] as FormData;
       expect(formData.get('includeAttachments')).toBe('false');
       expect(formData.get('maxAttachmentSizeMB')).toBe('20');
       expect(formData.get('downloadHtml')).toBe('true');
@@ -374,9 +401,9 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         );
       });
 
-      const formData = (mockedAxios.post as Mock).mock.calls[0][1] as FormData;
+      const formData = (mockedApiClient.post as Mock).mock.calls[0][1] as FormData;
       expect(formData.get('outputFormat')).toBe('pdfa');
-      expect(mockedAxios.post).toHaveBeenCalledWith('/api/v1/convert/pdf/pdfa', expect.any(FormData), {
+      expect(mockedApiClient.post).toHaveBeenCalledWith('/api/v1/convert/pdf/pdfa', expect.any(FormData), {
         responseType: 'blob'
       });
     });
@@ -418,7 +445,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         );
       });
 
-      const formData = (mockedAxios.post as Mock).mock.calls[0][1] as FormData;
+      const formData = (mockedApiClient.post as Mock).mock.calls[0][1] as FormData;
       expect(formData.get('fitOption')).toBe(FIT_OPTIONS.FIT_PAGE);
       expect(formData.get('colorType')).toBe('grayscale');
       expect(formData.get('autoRotate')).toBe('false');
@@ -455,7 +482,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
       });
 
       // Should make separate API calls for each file
-      expect(mockedAxios.post).toHaveBeenCalledTimes(2);
+      expect(mockedApiClient.post).toHaveBeenCalledTimes(2);
     });
   });
 
@@ -472,7 +499,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
       });
 
       // Mock one success, one failure
-      (mockedAxios.post as Mock)
+      (mockedApiClient.post as Mock)
         .mockResolvedValueOnce({
           data: new Blob(['converted1'], { type: 'application/pdf' })
         })
@@ -498,7 +525,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
       await waitFor(() => {
         // Should have processed at least one file successfully
         expect(operationResult.current.files.length).toBeGreaterThan(0);
-        expect(mockedAxios.post).toHaveBeenCalledTimes(2);
+        expect(mockedApiClient.post).toHaveBeenCalledTimes(2);
       });
     });
   });