diff --git a/web/src/lib/utils.ts b/web/src/lib/utils.ts
index d70aa265..185b41e2 100644
--- a/web/src/lib/utils.ts
+++ b/web/src/lib/utils.ts
@@ -5,3 +5,26 @@ export function cn(...inputs: ClassValue[]): string {
     return twMerge(clsx(inputs))
 }
 
+/**
+ * Decode base64 string to UTF-8 text
+ */
+export function decodeBase64(value: string): { text: string; ok: boolean } {
+    try {
+        const binaryString = atob(value)
+        const bytes = Uint8Array.from(binaryString, (char) => char.charCodeAt(0))
+        const text = new TextDecoder('utf-8').decode(bytes)
+        return { text, ok: true }
+    } catch {
+        return { text: '', ok: false }
+    }
+}
+
+/**
+ * Encode UTF-8 text to base64 string
+ */
+export function encodeBase64(value: string): string {
+    const bytes = new TextEncoder().encode(value)
+    const binaryString = Array.from(bytes, (byte) => String.fromCharCode(byte)).join('')
+    return btoa(binaryString)
+}
+
diff --git a/web/src/routes/sessions/file.tsx b/web/src/routes/sessions/file.tsx
index afb710e3..300f005d 100644
--- a/web/src/routes/sessions/file.tsx
+++ b/web/src/routes/sessions/file.tsx
@@ -9,18 +9,7 @@ import { useAppGoBack } from '@/hooks/useAppGoBack'
 import { useCopyToClipboard } from '@/hooks/useCopyToClipboard'
 import { queryKeys } from '@/lib/query-keys'
 import { langAlias, useShikiHighlighter } from '@/lib/shiki'
-
-function decodeBase64(value: string): { text: string; ok: boolean } {
-    try {
-        return { text: atob(value), ok: true }
-    } catch {
-        try {
-            return { text: decodeURIComponent(escape(atob(value))), ok: true }
-        } catch {
-            return { text: '', ok: false }
-        }
-    }
-}
+import { decodeBase64 } from '@/lib/utils'
 
 function decodePath(value: string): string {
     if (!value) return ''
diff --git a/web/src/routes/sessions/files.tsx b/web/src/routes/sessions/files.tsx
index 8e34b67c..a54e3ff4 100644
--- a/web/src/routes/sessions/files.tsx
+++ b/web/src/routes/sessions/files.tsx
@@ -7,14 +7,7 @@ import { useAppGoBack } from '@/hooks/useAppGoBack'
 import { useGitStatusFiles } from '@/hooks/queries/useGitStatusFiles'
 import { useSession } from '@/hooks/queries/useSession'
 import { useSessionFileSearch } from '@/hooks/queries/useSessionFileSearch'
-
-function encodePath(value: string): string {
-    try {
-        return btoa(value)
-    } catch {
-        return btoa(unescape(encodeURIComponent(value)))
-    }
-}
+import { encodeBase64 } from '@/lib/utils'
 
 function BackIcon(props: { className?: string }) {
     return (
@@ -255,8 +248,8 @@ export default function FilesPage() {
 
     const handleOpenFile = useCallback((path: string, staged?: boolean) => {
         const search = staged === undefined
-            ? { path: encodePath(path) }
-            : { path: encodePath(path), staged }
+            ? { path: encodeBase64(path) }
+            : { path: encodeBase64(path), staged }
         navigate({
             to: '/sessions/$sessionId/file',
             params: { sessionId },