Compress PNG
Cut PNG file size by resizing, or convert to WebP for the biggest savings.
Free · No watermark · Private — your image never leaves your browser
WebP has a full alpha channel, so transparent PNGs convert cleanly with no white box behind them and no fringing around soft edges.
Re-saving a PNG as PNG rarely helps much, so the tool defaults to the output that genuinely shrinks it rather than pretending otherwise.
Flat colour, hard edges and text are exactly what lossy formats mangle. Keeping lossless output preserves them where a JPEG would blur and halo.
How it works
Here's the thing most PNG compressors won't tell you plainly: PNG is lossless, so re-saving a PNG as a PNG achieves very little. The format already applies the best general-purpose compression it has, and running it again just repeats work. The real wins come from somewhere else — reducing the pixel dimensions, or moving to WebP, which keeps the transparency you needed PNG for while producing a file a fraction of the size. This tool defaults your PNG to WebP for exactly that reason, though you can keep PNG output if the destination demands it.
- 1Drop your PNG in — drag it, click to browse, or paste from the clipboard.
- 2Leave the output on WebP for the largest saving, or switch back to PNG if you need it.
- 3Compare the levels; for graphics with few colours the difference between them will be small.
- 4Download. Transparency is preserved either way.
Why re-saving a PNG barely helps
PNG compresses with DEFLATE, the same lossless algorithm behind ZIP, after a filtering step that makes pixel data more predictable. It's genuinely good at what it does — and that means an already-encoded PNG has very little redundancy left. Running it through another PNG encoder mostly re-does work already done. The savings people report from PNG optimisers come from a different trick entirely: reducing the colour palette, which is lossy in practice even though the format is lossless in principle.
What actually shrinks a PNG
Three things, in order of effect. Convert to WebP — lossless WebP typically beats PNG by 20 to 30 percent, and lossy WebP with alpha can be 70 percent smaller while looking identical. Reduce the dimensions — a screenshot from a high-DPI display is often twice the size it will ever be shown at. Reduce the colour count, if the image is a logo or icon with a handful of flat colours; PNG stores those far more efficiently than it stores photographic gradients.
When to keep PNG anyway
Some destinations still require it. Print workflows, older design software, certain marketplace and app-store upload forms, and anything expecting an exact pixel-for-pixel match will want PNG. It's also the right choice when you'll edit and re-save repeatedly, because lossless means no generation loss no matter how many times you save.
Frequently asked questions
Why is my compressed PNG barely smaller?
Because PNG is lossless and yours was already efficiently encoded — there's little redundancy left to squeeze. Switch the output to WebP, or reduce the pixel width. Either will do far more than another PNG pass.
Does WebP keep PNG transparency?
Yes, fully. WebP supports an 8-bit alpha channel, so soft shadows, feathered edges and cut-outs all convert cleanly. This is the main reason WebP replaced PNG for web graphics rather than sitting alongside it.
Is WebP or PNG better for screenshots?
Lossless WebP, if the destination accepts it — same pixel-perfect result, meaningfully smaller. Avoid lossy WebP and JPEG for screenshots: text and UI edges are precisely what they handle worst.
Will converting PNG to WebP lose quality?
Not if you keep it lossless — the result is pixel-identical. Lossy WebP does discard data, but at high quality settings the difference is invisible on photographic content. For flat graphics and text, stay lossless.
What if I need the file to stay a PNG?
Switch the output format back to PNG. Expect modest savings, and get the real reduction by lowering the pixel dimensions instead — that's the lever that works on a lossless format.
Is anything uploaded?
No. It runs in your browser, on your device. The PNG never crosses a network.