PERF-002
HTML document is very large
MediumDefault severity · Performance · SEO, quality and performance
Last reviewed
What it checks
Decompressed size of the HTML document.
Why it matters
Huge HTML (often inlined data or styles) slows parsing and first paint, especially on phones.
Recommended fix
Paginate or lazy-load large lists, and avoid inlining big JSON payloads or images.
How to verify
Check the document size in DevTools → Network and confirm it is under about 1 MB uncompressed.
Example fix prompt
Generic prompt (your report adds the evidence)
Please fix this production issue in my app.
Issue PERF-002: HTML document is very large
Site: https://your-app.example
First confirm the issue in the code or live config. If it is not present, say so and change nothing.
Task: Reduce the HTML size of the homepage: stop inlining large JSON data or base64 images in the page, paginate or lazy-load long lists, and only send the data the first screen needs.
Constraints: make the smallest change that fixes this, keep the current design and behaviour, never paste secret values into code or chat, and tell me which files you changed.
Done when: Check the document size in DevTools → Network and confirm it is under about 1 MB uncompressed.