Change WebP Quality

No. The entire re-encode runs in your browser via the 2D canvas API. The file is read, decoded, and compressed locally – there are no network requests for the image.

For web use, 70-85 is the usual sweet spot. 90-100 for archival or print, 40-60 for thumbnails. The stats line shows exactly how many bytes each setting saves against your source, so you can tune by eye.

WebP compresses efficiently – dropping from 95 to 75 usually halves the file with barely-visible artefacts. Test at your target quality and compare the preview against the original in a second tab.

No. The tool reads your file into memory and outputs a new Blob for preview and download. The file on disk is untouched until you decide to overwrite it.

Only the first frame is re-encoded. Canvas decodes animated WebP as a single still, so the output loses the animation.

You can choose quality 100, but that will not recover detail already lost to previous compression. It just produces a larger file that preserves the current pixels more faithfully.

If your source is already heavily compressed, re-encoding at a high quality can make the output larger. The stats line shows a positive byte delta so you notice immediately.

Yes – every slider change triggers a fresh re-encode (throttled to 100 ms) and the stats line updates with the actual output byte count. Nothing is estimated; those numbers come straight from the Blob.

No hard limit. Very large images (over 8000×8000 pixels) trigger a warning because memory caps vary by browser. Typical photos re-encode in well under 120 ms.

After the page loads, yes. HTML, CSS, and JS are self-contained, so you can disconnect Wi-Fi and keep optimising.