Scan a website for speed problems with ChatGPT

Scanning a site's speed with ChatGPT means connecting xSpeed as an MCP app and asking it to grade a URL, so the answer arrives in the chat as a score, the top fixes and a report link.

list_sitesget_speed_scanrun_speed_scan

Last updated: October 2026

Example session · ChatGPT

You: Use the xSpeed Scan MCP to scan my-store.example and tell me what to fix first.

run_speed_scan(url: my-store.example, strategy: both) read-only scan mcp
→ Desktop grade C, mobile grade D. Four failing checks, ranked: no page cache, image size (worst on mobile), then two smaller ones. Report link included.

ChatGPT: The top fix is serving the page from a cache instead of building it for every visitor. Second is image size, which hurts mobile most. The full report is at the link; share it with your developer.

You: Give me that as a checklist.

ChatGPT: Here is a checklist in the order the report ranks them: the page cache, then image size, then the two smaller checks the report names.

How ChatGPT handles this

This is the quick question you ask mid-conversation: why is this page slow, and what would I change first. With the xSpeed Scan MCP connected in ChatGPT, you paste the URL and ChatGPT calls run_speed_scan. The scan takes 20 to 60 seconds, then ChatGPT answers with a grade out of 100, the desktop run as the headline and mobile alongside, the failing checks and the report link on xspeedcache.com.

For ChatGPT the read-only route is the one to lead with. The Scan MCP has no account, no key and no tool that can change anything, so it avoids the question of write actions entirely. The Hub route works too, and it is the right one for your own sites: run_speed_scan takes a site handle, and get_speed_scan reads the scan history. But the Hub classes run_speed_scan as a write tool because it spends the shared speed-test allowance, and its tool definitions carry no read-only annotation. ChatGPT treats a tool without that annotation as a write action, so expect a confirmation for every Hub call, get_speed_scan included.

You can keep the conversation going after the scan. Ask ChatGPT to turn the failing checks into a to-do list, to explain one check in plain words, or to draft a message to the developer. The report also has a Markdown version at the same address with .md added, which suits pasting into the chat.

Set up ChatGPT once

Already connected? Skip to the prompts. Alternatives and troubleshooting are on the ChatGPT guide.

1Put your sites in xSpeed Hub

Sign in at app.xspeedcache.com with Google or email; the Hub is free and has no site cap. Then connect each WordPress site from its own dashboard: click Connect Hub in the xSpeed Cache top bar, then Connect via xSpeed Hub. Each site needs the free xSpeed Cache plugin.

2Turn on developer mode

In ChatGPT on the web, open Settings, then Security and login, and turn on Developer mode. On a Business workspace only admins and owners can use it. On Enterprise and Edu an admin grants access first, and you then turn it on under Settings, Apps, Advanced settings.

Text

Settings  >  Security and login  >  Developer mode

3Create the app from the Hub URL

Open ChatGPT Plugins, select the plus button and create a developer-mode app. Name it xspeedhub, paste the MCP server URL and choose OAuth. Click Scan Tools, approve access on the xSpeed Hub page that opens, wait for the scan to list the tools, then click Create. Workspace admins can also start from Workspace settings, Apps, Create.

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https://app.xspeedcache.com/xspeed/mcp

4Select the app in a chat

The app appears under Drafts in your app settings with a Dev label. In a new chat, open the plus menu in the composer, choose Developer mode and select xspeedhub. In a workspace, only an admin or owner can publish the app for other members.

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+  >  Developer mode  >  xspeedhub

5Add the xSpeed Scan MCP for sites you do not run

Prompts that scan a public URL use the xSpeed Scan MCP, a separate server from the Hub. Add it to ChatGPT the same way as the Hub above, as a second server (xspeedscan, for example) with the URL https://xspeedcache.com/scan/mcp, and leave out any sign-in setting, such as an OAuth or auth option or an Authorization header, because the Scan MCP needs no account, token or sign-in. On a plan that allows one custom connector, add whichever server the prompts you use need.

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https://xspeedcache.com/scan/mcp

1 / 5

Full ChatGPT setup, sign-in options and FAQ

Before you send a prompt that changes something

Reads change nothing on your sites, though contact_support emails xSpeed support. Writes run once your connection allows them, so your client's approval prompt and a read-only connection (the token's Read-only everywhere switch, or a Viewer sign-in) are the gates that matter. ChatGPT asks you to confirm write actions by default. You can expand a tool call to read the JSON it will send, and you can choose to remember an approve or deny choice for a tool for the rest of that conversation. ChatGPT respects a tool's read-only annotation and treats a tool without one as a write action; xSpeed Hub's tool definitions do not declare that annotation today, so expect confirmations on reads as well. OpenAI says confirmation also depends on app permissions and context, and some especially risky actions can be blocked. xSpeed Hub has no confirmation step of its own, so once you tell ChatGPT to remember Approve for a tool, that tool runs without a prompt for the rest of the conversation, as soon as your connection allows writes.

What do I ask?

Three prompts written for ChatGPT. More for this job are below.

Prompt for ChatGPT

Use the xSpeed Scan MCP to scan [your store URL] and tell me the grade for desktop and for mobile.

Prompt for ChatGPT

With the xSpeed Scan MCP, scan this URL, then turn the failing checks into a checklist I can give my developer.

Prompt for ChatGPT

Ask the xSpeed Scan MCP to scan it again on mobile only, with a fresh run, and tell me if anything changed.

What happens, step by step

An xSpeed Scan grades a site from 0 to 100 using server probes (time to first byte, compression, cache evidence, redirects, platform detection) plus a Lighthouse run, and names the fix for every failing check. An agent can start one two ways. Through xSpeed Hub, run_speed_scan scans a site you have connected. Through the no-account Scan MCP at https://xspeedcache.com/scan/mcp, it scans any public URL and cannot change anything. Either way you get a report link to share.

Check what the site already scored

get_speed_scan without a scan id returns the site's scan history, newest first, plus a summary of the latest report. It starts nothing and spends nothing, so the Hub tells the agent to read it first when you ask what a site scored.

Start a scan

run_speed_scan runs the full scan on a site you connected to the Hub. strategy is both (the default), desktop or mobile; one device alone costs half the engine's quota. The scan takes 20 to 60 seconds. The Hub waits about 50 seconds and, if the scan is still running, hands back a scan id.

Poll if it is still running

Call get_speed_scan with scan_id. While the scan runs it returns the running status and a note to ask again in about 20 seconds. The report page is live from the start and refreshes itself.

Read the result

The summary carries the grade, the four dimension scores, what was measured and the top fixes ranked by points recoverable, each with the xSpeed feature that fixes it. The headline grade is the desktop run. The mobile run is graded alongside it, so the agent should mention both when they differ.

Scan a site you do not run

For any other public URL, the agent uses the Scan MCP at https://xspeedcache.com/scan/mcp. There is no account and no sign-in. It takes a url, returns the same graded report and a link at xspeedcache.com/scan/r/<id>, and is limited to 4 scans per caller per 10 minutes.

Fix, wait, re-scan

After a change, wait several minutes and scan again with fresh: true. Without it, the scan service reuses any report from the last 10 minutes and the agent will show you the old number.

Reference

Hub route	run_speed_scan, then get_speed_scan with scan_id; only for sites connected to your Hub
Scan MCP route	https://xspeedcache.com/scan/mcp, no account, 5 tools, read-only, any public URL
Scan MCP limit	4 scans per caller per 10 minutes
Why run_speed_scan is a write	It spends a shared scan allowance and stores a report; it changes nothing on the site
Read-only Hub connection	run_speed_scan is refused; get_speed_scan still works. Applies to the connection token with Read-only everywhere on and to a Viewer sign-in; an OAuth sign-in gets the scopes the client asks for
Duration	20 to 60 seconds; the Hub waits about 50 seconds, then returns a scan id
Poll argument	scan_id on the Hub tool, scanId on the Scan MCP tool
strategy	both (default), desktop or mobile; one device costs half the quota and becomes the headline
fresh	true forces a new measurement; otherwise a report from the last 10 minutes is reused
Report link	xspeedcache.com/scan/r/<id>; add .md for a Markdown twin an agent can read
Report visibility	Hub scans are filed unlisted; Scan MCP scans are public in the scan directory by default

Rules worth keeping

Read before you spend. Ask for the scan history first; start a new scan only when you want a fresh measurement or something changed.
A report link is not private. An unlisted report is kept out of the scan directory and search, but anyone with the URL can open it. A scan started through the Scan MCP is public by default.
run_speed_scan changes nothing on your site, but the Hub classes it a write, so a read-only connection (the connection token with Read-only everywhere on, or a Viewer sign-in) refuses it and your client may prompt for it. Use get_speed_scan, or the Scan MCP for a public URL, when you want a strictly read-only route.
Compare like with like. A scan that lost its Lighthouse run is marked partial and is not comparable with a full one, and the lab grade is not the same as real-visitor Core Web Vitals, which the report shows separately.
A scan cannot reach private, local or password-protected sites, and a site behind a bot challenge returns a report that says its server checks were not measured.

Good to know with ChatGPT

Custom MCP apps need developer mode and work on the ChatGPT website only, not the mobile app. OpenAI's pages differ on plans: the developer-mode guide lists Pro, Plus, Business, Enterprise and Edu, while the help center calls full MCP with write actions a beta for Business, Enterprise and Edu and says Pro connects with read access. If run_speed_scan is missing from the Hub app, check your plan with OpenAI. Agent mode does not use custom apps, and deep research uses them for read and fetch only. ChatGPT's confirmation is your client's prompt, not something the Hub does: if you tell ChatGPT to remember Approve for run_speed_scan, later scans in that conversation run without asking and each one spends the shared allowance. ChatGPT signs in with OAuth and gets the scopes it asks for; the Hub's Read-only everywhere switch applies only to the connection token, which ChatGPT cannot send. For read-only Hub access, sign in as a Viewer member of the workspace, or keep ChatGPT's own confirmations on.

More prompts for this job

Prompts about your own sites work in any client connected to xSpeed Hub. A prompt that scans a site you do not run, or names the scan server, needs the xSpeed Scan MCP from the setup above.

Prompt

Using xSpeed Hub, what did the shop site score on its last speed scan? Do not start a new one.

Prompt

Use xSpeed Hub to run a speed scan on blog and give me the three fixes that recover the most points, plus the report link.

Prompt

With xSpeed Hub, scan only the mobile view of shop and tell me the grade.

Prompt

I changed the theme this morning. Use xSpeed Hub to run a fresh scan on docs and compare it with the previous report.

Prompt

Use the xSpeed Scan MCP to grade [competitor URL] and tell me what its biggest weaknesses are.

Prompt

The speed scan on shop is still running. Ask xSpeed Hub to check it again and tell me when it finishes.

Frequently asked questions

Use the Scan MCP to grade any public URL with no account, since it is read-only. Use xSpeed Hub when you want to scan your own sites by handle and read their scan history. Many people connect both.

It sees the same engine's result: grade, checks with evidence and the report link. Screenshots are not part of what the tool returns, so open the report link to look at them.

run_speed_scan runs the full xSpeed Scan: server probes plus Lighthouse, a 0 to 100 grade across four dimensions, the fix for every failing check and a shareable report link. run_speed_test returns a raw PageSpeed Insights score with Core Web Vitals and no graded report.

Yes, through the xSpeed Scan MCP at https://xspeedcache.com/scan/mcp. It needs no account and no sign-in, accepts any public URL and is read-only. The Hub route only scans sites you connected to your own workspace.

The Scan MCP allows 4 scans per caller per 10 minutes. Scanning the same URL again within 10 minutes returns the existing report unless the agent passes fresh: true. A Hub scan spends a shared allowance of the scan service, which is why the Hub treats it as a write tool.

Reports started from the Hub are filed as unlisted, which keeps them out of the public scan directory and search results, but the link itself still opens for anyone who has it. Reports started through the Scan MCP are public by default.

The headline grade is the desktop run, because it is the one you can reproduce in your own browser. The mobile run is graded on the same rubric and returned alongside it. Google ranks on mobile, so when the two differ the agent should tell you both.

Keep going

Scan a site's speed with other agents

More with ChatGPT

Purge the cache Find out why pages are not cached Track PageSpeed scores Raise the PageSpeed score Tune cache settings Warm the cache Set up Redis object cache Manage Cloudflare Manage every site at once

Documentation

From the blog

Scan a site's speed, from ChatGPT.

xSpeed Hub is free and has no site cap. Connect your sites once and ask from the agent you already use.

Open xSpeed Hub ChatGPT setup