diff --git a/config.ts b/config.ts
index 67b6a54..c4d6883 100644
--- a/config.ts
+++ b/config.ts
@@ -39,6 +39,7 @@ export type ConfigType = {
     check_file_hash: boolean;
     import_method: ImportMethod;
     max_import_img_count: number;
+    enable_server_timing: boolean;
 };
 
 export enum ThumbnailMethod {
@@ -239,6 +240,9 @@ export class Config {
     get max_import_img_count() {
         return this._return_number("max_import_img_count") || 3;
     }
+    get enable_server_timing() {
+        return this._return_bool("enable_server_timing") ?? false;
+    }
     to_json(): ConfigType {
         return {
             cookies: typeof this.cookies === "string",
@@ -277,6 +281,7 @@ export class Config {
             check_file_hash: this.check_file_hash,
             import_method: this.import_method,
             max_import_img_count: this.max_import_img_count,
+            enable_server_timing: this.enable_server_timing,
         };
     }
 }
diff --git a/routes/_middleware.ts b/routes/_middleware.ts
index 7a7c8b7..f63341d 100644
--- a/routes/_middleware.ts
+++ b/routes/_middleware.ts
@@ -13,6 +13,9 @@ const STATIC_FILES = ["/common.css", "/scrollBar.css", "/sw.js", "/sw.js.map"];
 
 export async function handler(req: Request, ctx: FreshContext) {
     const url = new URL(req.url);
+    const m = get_task_manager();
+    const enable_server_timing = m.cfg.enable_server_timing;
+    const start = enable_server_timing ? Date.now() : 0;
     if (url.pathname == "/sw.js") {
         build_sw();
     }
@@ -31,7 +34,6 @@ export async function handler(req: Request, ctx: FreshContext) {
         return get_file_response(file, opts);
     }
     if (url.pathname == "/flutter" || url.pathname.startsWith("/flutter/")) {
-        const m = get_task_manager();
         let flutter_base = import.meta.resolve("../static/flutter").slice(7);
         if (Deno.build.os === "windows") {
             flutter_base = flutter_base.slice(1);
@@ -66,7 +68,6 @@ export async function handler(req: Request, ctx: FreshContext) {
         return await get_file_response(p, opts);
     }
     if (url.pathname.startsWith("/canvaskit/")) {
-        const m = get_task_manager();
         let flutter_base = import.meta.resolve("../static/flutter").slice(7);
         if (Deno.build.os === "windows") {
             flutter_base = flutter_base.slice(1);
@@ -89,5 +90,16 @@ export async function handler(req: Request, ctx: FreshContext) {
         return await get_file_response(p, opts);
     }
     const res = await ctx.next();
+    if (enable_server_timing) {
+        if (res.status === 101) return res;
+        const headers = new Headers(res.headers);
+        const now = Date.now();
+        headers.append("Server-Timing", `total;dur=${now - start}`);
+        return new Response(res.body, {
+            status: res.status,
+            headers: headers,
+            statusText: res.statusText,
+        });
+    }
     return res;
 }
diff --git a/routes/api/_middleware.ts b/routes/api/_middleware.ts
index a34528b..ec9ef98 100644
--- a/routes/api/_middleware.ts
+++ b/routes/api/_middleware.ts
@@ -59,6 +59,8 @@ function handle_auth(req: Request, ctx: FreshContext) {
 
 export async function handler(req: Request, ctx: FreshContext) {
     const m = get_task_manager();
+    const enable_server_timing = m.cfg.enable_server_timing;
+    const start = enable_server_timing ? Date.now() : 0;
     if (!(handle_auth(req, ctx))) {
         const headers: HeadersInit = {};
         const origin = req.headers.get("origin");
@@ -67,6 +69,10 @@ export async function handler(req: Request, ctx: FreshContext) {
             headers["Access-Control-Allow-Origin"] = origin;
             if (c) headers["Access-Control-Allow-Credentials"] = "true";
         }
+        if (enable_server_timing) {
+            const end = Date.now();
+            headers["Server-Timing"] = `api;dur=${end - start}`;
+        }
         return return_error(401, "Unauthorized", 401, headers);
     }
     const res = await ctx.next();
@@ -86,6 +92,10 @@ export async function handler(req: Request, ctx: FreshContext) {
             if (c) headers.set("Access-Control-Allow-Credentials", "true");
             headers.set("Access-Control-Allow-Private-Network", "true");
         }
+        if (enable_server_timing) {
+            const end = Date.now();
+            headers.append("Server-Timing", `api;dur=${end - start}`);
+        }
         return new Response(null, { status: 204, headers });
     } else {
         if (res.status === 101) return res;
@@ -118,6 +128,10 @@ export async function handler(req: Request, ctx: FreshContext) {
                 }
             }
         }
+        if (enable_server_timing) {
+            const end = Date.now();
+            headers.append("Server-Timing", `api;dur=${end - start}`);
+        }
         return new Response(res.body, {
             status: res.status,
             headers: headers,
diff --git a/routes/api/files/[token].ts b/routes/api/files/[token].ts
index 25f8d2d..1f58910 100644
--- a/routes/api/files/[token].ts
+++ b/routes/api/files/[token].ts
@@ -12,6 +12,9 @@ export const handler: Handlers = {
         }
         const tokens = ctx.params.token.split(",");
         const m = get_task_manager();
+        const enable_server_timing = m.cfg.enable_server_timing;
+        const start = enable_server_timing ? Date.now() : 0;
+        const headers: HeadersInit = {};
         const data: EhFiles = {};
         for (const token of tokens) {
             data[token] = m.db.get_files(token).map((d) => {
@@ -22,6 +25,10 @@ export const handler: Handlers = {
                 return d;
             });
         }
-        return return_data(data);
+        if (enable_server_timing) {
+            const end = Date.now();
+            headers["Server-Timing"] = `db;dur=${end - start}`;
+        }
+        return return_data(data, 200, headers);
     },
 };