How it works

Re-encode an image as JPEG at the quality you choose, with a live preview of the file size savings.

Drag the quality slider (20 to 95, default 65) and the tool shows the before / after file size and the percentage saving as you move it. The image is decoded to a canvas and re-encoded as JPEG at the chosen quality. For most photos, dropping from 95 to 65 cuts file size in half with no visible difference. Going below 50 introduces visible artefacts but is fine for thumbnails. Output is always JPEG, so PNGs and other formats convert to JPEG too (the alpha channel is lost, white background substituted). For lossless compression or to keep the original format, use Convert image instead. Output filename has -compressed appended.

How to use it

1. Drop your image. Photos and screenshots both work; output is always JPEG.
2. Drag the quality slider. Watch the file size and saving percentage update live as you move it.
3. Find the sweet spot. 75-85 for photos that need to look good, 60-70 for thumbnails.
4. Download. The -compressed JPEG downloads, encoded entirely on a local canvas.

Frequently asked questions

What quality should I pick?

75-85 for photos that need to look good. 60-70 for web thumbnails. Below 50 starts to show JPEG artefacts.

Will my PNG keep its transparency?

No. Compress image always outputs JPEG, which doesn't support transparency. Transparent areas become white. For lossless or transparent compression, use Convert image with PNG or WebP.

How much smaller will the file get?

Depends on the source. A high-quality JPEG dropped from 95 to 65 typically saves 40-60%. A PNG photo converted to JPEG often shrinks by 80%+.

Is my image uploaded?

No. Compression happens in a canvas in your browser.