Bot signals · Web crawler

What is GTmetrix?

GTmetrix test servers

GTmetrix helps website owners test the performance of their web pages. Its test servers in locations around the world load the pages its users test.

risk.is_crawler

Official documentation All web crawlers

01 · Profile

GTmetrix at a glance.

What to look for in your logs, and what the lookup API returns for its addresses.

Type: Web crawler
API flag: risk.is_crawler

A user agent alone never sets a flag. Anyone can claim to be GTmetrix; the flag follows the address the request comes from.

02 · In the response

What a match looks like.

A lookup of a GTmetrix address sets risk.is_crawler. The flags come with geolocation and network data in the same response, for API keys on every paid plan.

The response says which kind of bot an address belongs to, not which operator. A request that claims to be GTmetrix while risk.is_crawler is false should not be trusted as GTmetrix.

GET /api/lookup/{ip}?key=YOUR_API_KEY

{
  // … location and network fields …
  "risk": {
    "is_ai": false,
    "is_crawler": true,
    "is_scanner": false
  }
}

03 · Control

Allow or block GTmetrix.

Your options

robots.txt works only for crawlers that choose to follow it. Check the operator’s documentation for the token it reads.
Firewall, WAF or CDN. Many offer bot rules you can allow or deny by category. Use them to enforce what robots.txt only asks for.
In your app. Look up the client address and allow or deny on risk.is_crawler, alongside the user agent.
Never on the user agent alone. Blocking the name stops only honest clients; allowing it lets anyone in who borrows it.