Lighthouse-lite Performance Checker

Analyze pasted HTML (or fetch when CORS allows) for title, viewport, alt coverage, script count, and size. Heuristic HTML performance/SEO checks inspired by Lig

Introduction

Lighthouse-lite Performance Checker is a free, browser-based utility in our Validator Tools collection. Analyze pasted HTML (or fetch when CORS allows) for title, viewport, alt coverage, script count, and size. Lighthouse-lite Performance Checker provides quick HTML heuristics - not a full Chromium Lighthouse lab run. Everything runs locally in your browser — inputs stay on your device, with no account or upload required. Highlights include score summary.

Features

Score summary
HTML paste
Optional fetch

How to use

1
Paste HTML or try Fetch URL.
2
Read the lite score.

Example

Page HTML

Input

<html>..

Output

Lite score /100

Benefits

Run Lite Perf entirely in the browser with no signup or installation.
Keep sensitive sample data private — processing never leaves your device.
Score summary
HTML paste
Optional fetch
Pair it with A11y Check and Meta Preview when your workflow needs adjacent utilities.

FAQs

No - heuristics only.

Many sites block browser fetch; paste HTML instead.

No.

Yes. Lite Perf on EverydayDevTools is free, with no account, watermarks, or usage caps for normal interactive use.

No. Lite Perf runs in your browser. Your input is processed locally and is not sent to EverydayDevTools servers.

Analyze pasted HTML (or fetch when CORS allows) for title, viewport, alt coverage, script count, and size. It fits everyday validator tools tasks when you want a fast local utility instead of installing a CLI or opening a heavy IDE feature.

Core capabilities include: Score summary; HTML paste; Optional fetch.

Developers often pair Lite Perf with A11y Check, Meta Preview, HTML Formatter. Open Related tools on this page for quick links.