The Speed Doctor

What you get

Your website is slow, and the speed report makes no sense.

The Speed Doctor reads it for you.

It connects Claude to Chrome's built-in developer tools. That kind of connection is called an MCP.

Claude runs Google's Lighthouse check on your page. Lighthouse is Google's free speed and quality checker.

Then Claude edits your files to fix what failed:

• Smaller images
• Lighter scripts
• Missing alt text (the words that describe a picture)

On one badly built page, Accessibility went from 38 to 100.

Free. No keys. No accounts. About 10 minutes.

One thing to know

Real sites rarely jump that far.

The Chrome connection does not print a speed score. That is why Step 3 adds Lighthouse.

Claude can only fix files it has. Run it on a copy of your site.

It runs on your own computer. Nothing is uploaded.

Who this is for

You have a website that you or your developer can edit.

This replaces reading a speed report you don't understand, then chasing someone to fix it.

What you need

• Claude Code
• Node 20 or newer
• Google Chrome
• A copy of your site's files on your computer

Set it up

Open a terminal. That is the app where you type commands.

Step 1: Add the Chrome connection

It connects Claude to Chrome. The first start is slow because it downloads the tool.

claude mcp add chrome-devtools --scope user -- npx chrome-devtools-mcp@latest

Step 2: Restart Claude Code

Close it. Open it again. Or the new tools won't appear.

Step 3: Install Lighthouse

This gives you the 0 to 100 speed score.

npm install -g lighthouse

Use it

Go to your site's folder. Ask Claude:

"Run a Lighthouse audit on my page in Chrome, fix what's failing in the code, then run it again."

Here is what you see:

Accessibility   38 -> 100
SEO             82 -> 100
Speed score     25 -> 100
Load time       137.7 s -> 0.9 s

If something goes wrong

The Chrome tools don't show up. Restart Claude Code after Step 1.

Claude says it can't fix the page. It only has your live address. Start Claude Code inside the folder with your site's files.

Credit

Built by the Chrome DevTools team (https://github.com/ChromeDevTools/chrome-devtools-mcp), Apache-2.0 license. Free and open source.