Fetch & Render Simulator
Tool designed to simulate the googlebot fetch & render. Will return rendered, and initial
source code (obeys the user-agent specified) and a screenshot.
Optionally you can also run a lighthouse test as well. Although intended to match, parity with the Google WRS cannot be guaranteed, always confirm in either the Mobile-Friendly Test or URL Inspection tool in Search Console.
Honour robots.txt uses the google open source parser, robots.txt files are fetched fresh for each test.
Test results deleted after 5 mins max, tests are not logged.
URL is required
Lighthouse tests will be mobile for mobile user-agents, desktop for desktop
Flattening the DOM will pierce the Shadow DOM, and also render content of iframes EXPERIMENTAL
Overlay / Output Core Web Vitals will show LCP element, any LCP Shift & FID (basically runs this bookmarklet you can run in you browser).
User Agent / Referrer
Uses these excellent open source projects:
for robots.txt parsing and matching &
for DOM flattening.
iframe flattening inspired by a discussion with Glenn Gabe ( @glenngabe ), of G-Squared Interactive