Online Tool Store
HTML Size Analyzer
Paste HTML source and see its raw byte size, estimated gzip size, tag count, and inline script/style count. Runs entirely in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
- Raw size
- Est. gzip size
- Tag count
- Inline scripts/styles
Gzip estimate uses a typical ~70% compression ratio for HTML text — for an exact figure, check your server's actual response headers.
How it works
- Paste the HTML source of a page (view-source works well).
- The tool measures its raw UTF-8 byte size and estimates the gzip-compressed size.
- It also counts total tags and inline
<script>/<style>blocks, both signals of page weight.
FAQ
Why is the gzip size only an estimate?
Real gzip compression depends on the actual byte patterns in your file, which varies page to page. A ~70% reduction is a reasonable rule of thumb for typical HTML, but your server's actual Content-Encoding response is the ground truth.
Why does tag count matter for performance?
More DOM nodes means more work for the browser to parse, style, and lay out — very large tag counts (several thousand) can noticeably slow down rendering.
Should I worry about inline scripts and styles?
A few are fine, but many inline blocks bloat the initial HTML payload and can't be cached separately the way an external .css or .js file can.
Is my HTML source sent anywhere?
No — byte size is measured with TextEncoder and the rest is computed with regular expressions, entirely in your browser.
How we compare
| Feature | Online Tool Store | Browser DevTools Network tab | curl + wc -c |
|---|---|---|---|
| Works from pasted source, no live page needed | ✓ | ✗ | ✗ |
| Tag count + inline script/style breakdown | ✓ | ✗ | ✗ |
| No terminal required | ✓ | ✓ | ✗ |
If you want a quick page-weight gut check without opening DevTools or a terminal, pasting the source here gets you there in seconds.