Load-Watt

Target file

profile a page of your own

⇩

Drag & drop an .html file here, or browse

or measure a public repo

No file loaded. Drop an .html file, or point at a public GitHub repo above, and it's auto-instrumented: every setInterval/setTimeout/requestAnimationFrame callback and DOM event listener is timed automatically, plus any top-level function it defines. Page-load timing (paint, long tasks, layout shift) is also picked up with no changes needed. For a repo, the entry HTML's relative <script>/<link>/<img> references are rewritten to load straight from cdn.jsdelivr.net, so its real CSS/JS/assets load too — only that one HTML document's own top-level functions get auto-wrapped, though.

Composite indices

estimated

Power draw index0/100

nominal

Lag index0/100

nominal

Live channels

last ~2 min

CH.1 — Frame time—

CH.2 — Main-thread busy—

CH.3 — Network throughput—

CH.4 — JS heap—

CH.5 — Render / compositor load—

Readouts

session totals & snapshots

Process bench

run known antipatterns, watch the channels react

Process	Calls	Total ms	Avg ms	Session share	Impact
No processes run yet — try a preset above.

Custom process (advanced — runs your own JS in this page)

Executes with new Function() in your own browser tab. No data leaves this page.

Diagnostic log

0 events

—No long tasks or shifts detected yet.

Tuning recommendations

refreshes every 5s

Start recording — recommendations appear once enough data has been collected.