diff --git a/tools/server/webui/src/lib/utils/base64.ts b/tools/server/webui/src/lib/utils/base64.ts
deleted file mode 100644
index e825e16086..0000000000
--- a/tools/server/webui/src/lib/utils/base64.ts
+++ /dev/null
@@ -1,29 +0,0 @@
-/**
- * Decode base64 to UTF-8 string using modern APIs.
- * Falls back to legacy method if TextDecoder is unavailable.
- *
- * @param base64 - Base64 encoded string (padding is optional)
- * @returns Decoded UTF-8 string, or empty string if decoding fails
- */
-export function decodeBase64(base64: string): string {
-	if (!base64) return '';
-
-	const padded = base64 + '=='.slice(0, (4 - (base64.length % 4)) % 4);
-
-	try {
-		const binaryString = atob(padded);
-		const bytes = new Uint8Array(binaryString.length);
-		for (let i = 0; i < binaryString.length; i++) {
-			bytes[i] = binaryString.charCodeAt(i);
-		}
-		return new TextDecoder('utf-8').decode(bytes);
-	} catch {
-		// Fallback to legacy method
-		try {
-			return decodeURIComponent(escape(atob(padded)));
-		} catch {
-			// Return empty string if all decoding fails
-			return '';
-		}
-	}
-}
diff --git a/tools/server/webui/src/lib/utils/chat-stream.ts b/tools/server/webui/src/lib/utils/chat-stream.ts
deleted file mode 100644
index 44145348b2..0000000000
--- a/tools/server/webui/src/lib/utils/chat-stream.ts
+++ /dev/null
@@ -1,85 +0,0 @@
-import type {
-	ApiChatCompletionResponse,
-	ApiChatCompletionStreamChunk,
-	ApiChatCompletionToolCall,
-	ApiChatCompletionToolCallDelta
-} from '$lib/types/api';
-
-export function mergeToolCallDeltas(
-	existing: ApiChatCompletionToolCall[],
-	deltas: ApiChatCompletionToolCallDelta[],
-	indexOffset = 0
-): ApiChatCompletionToolCall[] {
-	const result = existing.map((call) => ({
-		...call,
-		function: call.function ? { ...call.function } : undefined
-	}));
-
-	for (const delta of deltas) {
-		const index =
-			typeof delta.index === 'number' && delta.index >= 0
-				? delta.index + indexOffset
-				: result.length;
-
-		while (result.length <= index) {
-			result.push({ function: undefined });
-		}
-
-		const target = result[index]!;
-
-		if (delta.id) {
-			target.id = delta.id;
-		}
-
-		if (delta.type) {
-			target.type = delta.type;
-		}
-
-		if (delta.function) {
-			const fn = target.function ? { ...target.function } : {};
-
-			if (delta.function.name) {
-				fn.name = delta.function.name;
-			}
-
-			if (delta.function.arguments) {
-				fn.arguments = (fn.arguments ?? '') + delta.function.arguments;
-			}
-
-			target.function = fn;
-		}
-	}
-
-	return result;
-}
-
-export function extractModelName(
-	data: ApiChatCompletionStreamChunk | ApiChatCompletionResponse | unknown
-): string | undefined {
-	const asRecord = (value: unknown): Record<string, unknown> | undefined => {
-		return typeof value === 'object' && value !== null
-			? (value as Record<string, unknown>)
-			: undefined;
-	};
-
-	const getTrimmedString = (value: unknown): string | undefined => {
-		return typeof value === 'string' && value.trim() ? value.trim() : undefined;
-	};
-
-	const root = asRecord(data);
-	if (!root) return undefined;
-
-	const rootModel = getTrimmedString(root.model);
-	if (rootModel) return rootModel;
-
-	const firstChoice = Array.isArray(root.choices) ? asRecord(root.choices[0]) : undefined;
-	if (!firstChoice) return undefined;
-
-	const deltaModel = getTrimmedString(asRecord(firstChoice.delta)?.model);
-	if (deltaModel) return deltaModel;
-
-	const messageModel = getTrimmedString(asRecord(firstChoice.message)?.model);
-	if (messageModel) return messageModel;
-
-	return undefined;
-}
diff --git a/tools/server/webui/src/lib/utils/index.ts b/tools/server/webui/src/lib/utils/index.ts
index 3b2488b840..47040f8723 100644
--- a/tools/server/webui/src/lib/utils/index.ts
+++ b/tools/server/webui/src/lib/utils/index.ts
@@ -104,12 +104,6 @@ export { isTextFileByName, readFileAsText, isLikelyTextFile } from './text-files
 // Agentic utilities
 export { toAgenticMessages, getAgenticConfig } from './agentic';
 
-// Base64 utilities
-export { decodeBase64 } from './base64';
-
-// Chat stream utilities
-export { mergeToolCallDeltas, extractModelName } from './chat-stream';
-
 // Debounce utilities
 export { debounce } from './debounce';