Make a graphic, icon or screenshot lighter by giving it fewer colours to store.
PNG has no quality dial, so the only way to make one smaller is to give it fewer colours to store.
A screenshot of a form, a flat logo or a chart contains a few dozen real colours and millions of pixels that repeat them. A file exported from a design tool usually describes every pixel in full colour anyway. Rebuilding it on the palette it actually uses is where the bytes disappear — 50–80% is common on graphics of this kind.
The smaller file stays a PNG with a real alpha channel, so the cut-out background of a logo or an icon survives and the picture can still be dropped onto any colour. Nothing turns into a white rectangle, which is what happens the moment a transparent graphic becomes a JPG.
App store screenshots, documentation images, help-centre graphics and interface mockups are all PNG by convention, and all of them get better when they weigh less. The picture looks the same; the page opens faster and the upload stops timing out.
It sets how many colours the result may keep — not how much detail is thrown away.
At 75 — the default — the image is rebuilt on a palette that fits what it contains, which is usually 256 colours or fewer. Flat graphics, interface screenshots and logos with a limited palette lose almost nothing visible. Every remaining pixel is still stored exactly, so the format stays lossless in the usual sense.
A photograph contains thousands of tones, so reducing it to a palette produces banding in skies, skin and shadows, and the dithering used to hide that adds noise that can make the file no smaller at all. If the picture is photographic, this is the wrong tool — the format is the problem, not the setting.
A 3000 px wide screenshot displayed at 1000 px carries nine times the pixels anyone sees. Capping the maximum width shrinks it before anything else happens, and works on every kind of image, photographs included. Images are never enlarged, so a value above the original simply does nothing.
When the palette trick gains nothing, the original comes back untouched and is flagged as already optimised. The result line shows the exact before and after weight, so you can see whether the run was worth it before saving anything.
Three steps, and the preview tells you if it worked.
Drag it onto the box, click to browse, or paste it with Ctrl+V (Cmd+V on a Mac). One file per run, up to 25 MB. Any transparency in the file is kept.
The default quality is a good first attempt for a graphic. If the file is still heavy and far wider than it needs to be, set a maximum width as well: 1600 px is generous for a screenshot, 600 px is plenty for an icon in a help article.
Look at the preview for banding in gradients before saving. One click downloads the result with the original name — the untouched original is still on your device if you want to try a different setting.
The format you pick matters more than the setting you choose.
Palette banding is obvious at 400% and invisible at the size the image actually appears. Zoom to the real display size before deciding that a setting went too far — and keep the original until you are sure, because a quantised PNG cannot be expanded back to the colours it lost.
A photographic PNG is heavy because PNG is lossless. The real answer is PNG to WebP for the web — usually under a tenth of the weight, transparency included — or PNG to JPG when the file has to open anywhere, and then compressing the JPG if it is still too large.
Compressing the same PNG twice quantises an already quantised palette, and the second pass can add visible noise. Archive the untouched file and publish the compressed one; if a later use needs full colour, the archive still has it.
Yes. There is no account, no trial, no credit card and no watermark, and the number of files is not capped. A short rate limit keeps the service usable for everyone else.
Because PNG is lossless and the only saving available is fewer colours. A screenshot or a flat logo has a small palette and shrinks a lot; a photograph has thousands of tones, so quantising either does nothing useful or introduces banding, and the tool returns the original when it cannot beat it. For a photo, converting to WebP or JPG is the real fix.
Yes. The compressed file is still a PNG with an alpha channel, so cut-out areas stay cut out and can be placed on any background colour. The palette is rebuilt with transparency in mind, so the soft edge of a logo keeps its gradual fade instead of turning into a hard outline.
Up to 25 MB per file, with the image itself limited to 50 megapixels and an optional maximum width of 8000 px. Screenshots from high-density displays can be much wider than they are ever shown, so capping the width is often the biggest single saving.
Files are processed on our server and not stored. The PNG is re-encoded as it arrives and only the compressed copy is sent back to your browser.
