Connect ChatGPT to the Uiprobe MCP server

Connect ChatGPT to the Uiprobe MCP server to compare a Figma frame with a live webpage from a chat. ChatGPT runs the probe, waits for the result and reads the findings back to you.

Once Uiprobe is connected, you can ask ChatGPT to:

• run a new probe from a Figma frame URL and a webpage URL
• re-run an existing probe after the page has changed
• list your probes, including your team's probes
• show the findings of a probe, with the design value and the page value for each one
• show the screenshots that go with a finding

What you need

• ChatGPT in a browser for the setup, at chatgpt.com. Developer mode can only be turned on there, not in the ChatGPT desktop app. Once Uiprobe is added, you can use it in the desktop app too.
• A Uiprobe account. If you don't have one yet, sign up at app.uiprobe.io with Figma first. ChatGPT can only connect to an existing account.
• A webpage URL that is publicly reachable. We capture the page from our own servers, so we can't open localhost, private network or VPN-only addresses. Use a staging or preview deployment, or a tunnel for a page that runs on your computer (see below).

ChatGPT changes its menus and settings regularly. These steps were checked in October 2026, so a label or menu may look slightly different for you. If you can't find a step, contact support@uiprobe.io and we'll help you connect.

Turn on developer mode

1. Open chatgpt.com in your browser.
2. Click your name in the bottom left corner and open Settings.
3. Go to Security and login and scroll down to Developer mode.
4. Turn on Developer mode.

If you don't see the option in a ChatGPT Business or Enterprise workspace, your workspace admin has to allow it first.

Add the Uiprobe server

1. Click Plugins in the sidebar.
2. Click + next to the search field and choose Add custom MCP server.

3. A New Plugin window opens with an area to drop a plugin file. You don't need a file: click Create MCP App.

4. Fill in the fields:
   • Name: Uiprobe
   • Description: Compare Figma designs with live webpages
   • Connection: choose Server URL and enter https://app.uiprobe.io/mcp
   • Authentication: OAuth

5. Read the warning about custom MCP servers and tick I understand and want to continue.
6. Click Create.

Sign in

ChatGPT opens a sign-in window. Sign in with the Figma account you use for Uiprobe and approve access. When the window closes, Uiprobe shows up under Installed on the Plugins page.

Use Uiprobe in a chat

1. Start a new chat, in the browser or in the ChatGPT desktop app.
2. Click + in the message box and select Uiprobe.

3. Ask for what you need. For example:
   • "Compare this Figma frame with this page: [Figma URL] [webpage URL]"
   • "List my Uiprobe probes"
   • "Run the checkout probe again and tell me what changed"
   • "Show me the findings about font size, with screenshots"

Copy the Figma link from the frame itself: select the frame in Figma and press Cmd+L (Ctrl+L on Windows). A link to the whole file doesn't tell us which frame to compare.

Probe a page that runs on your computer

ChatGPT can't reach a page on localhost, and it can't run commands on your computer. You can make the page reachable yourself with a free Cloudflare tunnel. You don't need a Cloudflare account.

1. Install cloudflared. On a Mac, run brew install cloudflared. For Windows and Linux, see Cloudflare's download page.
2. Start your dev server as usual.
3. In a terminal, run cloudflared tunnel --url http://localhost:3000 --http-host-header localhost. Replace 3000 with the port your page runs on.
4. Copy the https://…trycloudflare.com address it prints and give it to ChatGPT as the webpage URL.
5. Keep the tunnel running until ChatGPT has the result, then stop it with Ctrl+C.

While the tunnel runs, anyone with the address can open your page. A tunnel doesn't get past a login: a page behind a login is captured as its login page. Each new tunnel gets a new address, so when you run the probe again later, give ChatGPT the new address.

What happens next

ChatGPT may ask you to confirm before it calls Uiprobe. You can change when it asks under Settings, Plugins, Uiprobe, Permissions.

A probe usually takes a few minutes. ChatGPT waits for the result, then summarizes the findings with a link to open the probe in Uiprobe. There you can review every finding on the canvas in the Probe Inspector.

Each new run counts toward your plan's runs, the same as a run from the web app. When you change the page, ask ChatGPT to run the existing probe again. The new run is added as a new version of the same probe, so you keep the history.

If something doesn't work

The sign-in window says "Your session expired". Close it and try again from Settings, Plugins, Uiprobe. If it happens again, contact support@uiprobe.io.

Sign-in works, but ChatGPT can't reach Uiprobe. The Figma account you signed in with has no Uiprobe account yet. Sign up at app.uiprobe.io with that Figma account, then connect again.

ChatGPT says the webpage is not accessible. The page has to load for a visitor on the open internet. Pages behind a login or on a private network can't be captured. For a page on localhost, use a tunnel as described above.

ChatGPT says the Figma frame is not accessible. Check that the Figma account you signed in with can open the file. If it can, sign in again so we get a fresh Figma connection.

ChatGPT says you are out of runs. Your plan's runs are used up. You can still list probes and read their findings.

Next steps

Continue with:

• Re-run a probe and compare versions