diff --git a/frontend/.gitignore b/frontend/.gitignore
index a547bf36d..b02a1ff77 100644
--- a/frontend/.gitignore
+++ b/frontend/.gitignore
@@ -11,6 +11,7 @@ node_modules
 dist
 dist-ssr
 *.local
+package-lock.json
 
 # Editor directories and files
 .vscode/*
diff --git a/frontend/src/components/ChatBox.tsx b/frontend/src/components/ChatBox.tsx
index aecde7b7b..2d34fb87c 100644
--- a/frontend/src/components/ChatBox.tsx
+++ b/frontend/src/components/ChatBox.tsx
@@ -86,6 +86,7 @@ interface SelectedFile {
   uploadError?: string
   preview?: string // URL for image preview
   fileType?: FileType
+  abortController?: AbortController // For cancelling ongoing uploads
 }
 
 export const getFileIcon = (fileType: FileType | string | undefined) => {
@@ -832,24 +833,36 @@ export const ChatBox = React.forwardRef<ChatBoxRef, ChatBoxProps>(
         setUploadingFilesCount((prev) => prev + files.length)
         const uploadedMetadata: AttachmentMetadata[] = []
 
-        // Set all files to uploading state
+        // Create AbortControllers for each file before starting uploads
+        const fileAbortControllers = new Map<string, AbortController>()
+        files.forEach(file => {
+          fileAbortControllers.set(file.id, new AbortController())
+        })
+
+        // Set all files to uploading state and store AbortControllers
         setSelectedFiles((prev) =>
-          prev.map((f) =>
-            files.some((file) => file.id === f.id)
-              ? { ...f, uploading: true, uploadError: undefined }
-              : f,
-          ),
+          prev.map((f) => {
+            const abortController = fileAbortControllers.get(f.id)
+            if (abortController) {
+              return { ...f, uploading: true, uploadError: undefined, abortController }
+            }
+            return f
+          }),
         )
 
         const uploadPromises = files.map(async (selectedFile) => {
+          const abortController = fileAbortControllers.get(selectedFile.id)
+          
           try {
             const formData = new FormData()
             formData.append("attachment", selectedFile.file)
+            
             const response = await authFetch(
               "/api/v1/files/upload-attachment",
               {
                 method: "POST",
                 body: formData,
+                signal: abortController?.signal,
               },
             )
 
@@ -865,7 +878,7 @@ export const ChatBox = React.forwardRef<ChatBoxRef, ChatBoxProps>(
               setSelectedFiles((prev) =>
                 prev.map((f) =>
                   f.id === selectedFile.id
-                    ? { ...f, uploading: false, metadata }
+                    ? { ...f, uploading: false, metadata, abortController: undefined }
                     : f,
                 ),
               )
@@ -874,12 +887,17 @@ export const ChatBox = React.forwardRef<ChatBoxRef, ChatBoxProps>(
               throw new Error("No document ID returned from upload")
             }
           } catch (error) {
+            // If the upload was aborted, don't show error
+            if (error instanceof Error && error.name === 'AbortError') {
+              return null
+            }
+            
             const errorMessage =
               error instanceof Error ? error.message : "Upload failed"
             setSelectedFiles((prev) =>
               prev.map((f) =>
                 f.id === selectedFile.id
-                  ? { ...f, uploading: false, uploadError: errorMessage }
+                  ? { ...f, uploading: false, uploadError: errorMessage, abortController: undefined }
                   : f,
               ),
             )
@@ -980,6 +998,11 @@ export const ChatBox = React.forwardRef<ChatBoxRef, ChatBoxProps>(
     const removeFile = useCallback(async (id: string) => {
       const fileToRemove = selectedFiles.find((f) => f.id === id)
       
+      // If the file is currently uploading, abort the upload
+      if (fileToRemove?.uploading && fileToRemove?.abortController) {
+        fileToRemove.abortController.abort()
+      }
+      
       // If the file has metadata with fileId (meaning it's already uploaded), delete it from the server
       if (fileToRemove?.metadata?.fileId) {
         try {
@@ -1005,7 +1028,12 @@ export const ChatBox = React.forwardRef<ChatBoxRef, ChatBoxProps>(
         if (fileToRemove?.preview) {
           URL.revokeObjectURL(fileToRemove.preview)
         }
-        return prev.filter((f) => f.id !== id)
+        const filtered = prev.filter((f) => f.id !== id)
+        // Decrement uploadingFilesCount if the file was uploading
+        if (fileToRemove?.uploading) {
+          setUploadingFilesCount((count) => Math.max(0, count - 1))
+        }
+        return filtered
       })
     }, [selectedFiles])
 
@@ -2862,7 +2890,7 @@ export const ChatBox = React.forwardRef<ChatBoxRef, ChatBoxProps>(
                         <button
                           onClick={() => removeFile(selectedFile.id)}
                           className="absolute top-1 right-1 bg-black bg-opacity-60 text-white rounded-full p-1 hover:bg-opacity-80 transition-opacity"
-                          disabled={selectedFile.uploading}
+                          title={selectedFile.uploading ? "Cancel upload" : "Remove file"}
                         >
                           <X size={10} />
                         </button>
@@ -2918,7 +2946,7 @@ export const ChatBox = React.forwardRef<ChatBoxRef, ChatBoxProps>(
                           <button
                             onClick={() => removeFile(selectedFile.id)}
                             className="text-gray-400 hover:text-red-500 transition-colors p-1"
-                            disabled={selectedFile.uploading}
+                            title={selectedFile.uploading ? "Cancel upload" : "Remove file"}
                           >
                             <X size={12} />
                           </button>