Introducing SEO JavaScript Checker - a Chrome extension, designed to compare the raw server HTML with the live, client-rendered DOM and highlight differences.
@rustybrick It turns out that the Weekly and Monthly views show the missing data more cleanly (but still joins March to June) - personally, I think I'd prefer the trend going to zero during the period of missing data instead of joining the two months up. It would be more honest.
What's wrong with this picture? Not sure if this is new or not, but take a look at this GSC screenshot.
The x-axis is from Feb. 2025 to June 2025, but the date range skips April and May completely, and the resulting trend lines join March straight to June! @rustybrick
I've heard many talks today at #BrightonSEO referencing how AI bots struggle with JS rendering. My new Chrome plug-in might help you all...
https://t.co/1KXcmnHIRj
Introducing SEO JavaScript Checker - a Chrome extension, designed to compare the raw server HTML with the live, client-rendered DOM and highlight differences.
Introducing SEO JavaScript Checker - a Chrome extension, designed to compare the raw server HTML with the live, client-rendered DOM and highlight differences.
Introducing SEO JavaScript Checker - a Chrome extension, designed to compare the raw server HTML with the live, client-rendered DOM and highlight differences.
If you care about how your pages are understood by both search engines and AI crawlers, this helps bridge that gap.
Grab it from the Chrome Web Store now: https://t.co/1KXcmnHb1L
What it does
- Compares server vs. rendered HTML
- Flags changed, added, or removed elements
- Works on nearly any HTTPS page
- Exports reports for QA or documentation
- Lightweight, private, and built for real-world debugging - no dependencies, no data collection, no setup.
It highlights EVERY difference in head tags, visible text and links so you can immediately see what changed after JavaScript ran.
It’s awesome at debugging rendering parity issues and catching metadata regressions before they affect indexing or AI visibility.
I got tired of spending ages trying to determine what Google and emerging AI models like ChatGPT, Perplexity and Gemini actually see, so I built SEO JS Checker, a Chrome extension that compares the raw server HTML with the live, client-rendered DOM.
AI crawlers, particularly those associated with LLMs and AI-powered search engines, often encounter challenges with JS-heavy content. While advanced search engines like Google have made significant progress in rendering and understanding JS, many AI crawlers struggle.
More sites than ever rely on JavaScript frameworks like React, Next.js, Shopify front-ends, complex tag managers, and they often rewrite key HTML. That’s fine for users, but it creates uncertainty for both search engines and AI crawlers about what your page really contains.
@screamingfrog FYI - I noticed that the "JavaScript: Pages with Blocked Resources" report didn't export. There are 127 instances shown in the UI. Trying to export just this report manually gives me the same "Export Failure" error as before.