Compress PNG online
Drop in your .png files and download smaller versions with the transparent background intact. Output is set to PNG already; switch it to WebP if you want a much bigger saving and still need transparency.
Your PNGs are processed inside this browser tab. Nothing is uploaded to a server, and nothing is stored anywhere.
What actually shrinks a PNG
PNG is lossless: it stores every pixel exactly, and gets its savings from spotting repetition — long runs of the same colour, rows that resemble the row above. That is why a flat logo compresses to almost nothing while a photograph saved as PNG stays enormous. Re-encoding a PNG as PNG can only re-run that search for repetition, so the saving is modest, sometimes zero. The three things that genuinely make a PNG smaller are fewer colours, fewer pixels, and switching to a format that is allowed to discard detail.
Questions about PNG compression
Why is the quality slider greyed out for PNG?
Because PNG has no quality setting to adjust. The format is lossless by definition — the decoder must reproduce every original pixel exactly — so there is no dial to turn between "detailed" and "small". The slider comes back to life the moment you pick WebP or JPEG, both of which are allowed to approximate.
My PNG barely got smaller. What should I do?
Switch the output format to WebP. Lossy WebP keeps the transparent background but is permitted to approximate the pixels, and a PNG screenshot or illustration commonly drops by 70–90%. Every browser released in the last several years displays WebP, and so do Windows, macOS, iOS and Android. Keep PNG only where you need maximum compatibility — some older desktop software, print workflows and a few upload forms still insist on it.
Does the transparent background survive?
With PNG and WebP output, yes — the alpha channel is carried through untouched. With JPEG output it cannot, because the format has no way to store transparency; anything see-through is flattened onto white. If your logo suddenly has a white box around it, that is the reason, and the fix is to choose PNG or WebP.
Is a screenshot better kept as PNG or converted?
Keep screenshots that contain text as PNG or lossless-looking WebP. Lossy compression works by rounding off fine detail, and the sharpest detail in a screenshot is the edge of every letter, so text is exactly what it damages first — you get a faint coloured haze around the characters. Photographs have no such hard edges and convert to JPEG happily.
Does converting a photo to PNG make it smaller?
No, it usually makes it several times bigger. A camera photo is already stored as a JPEG that discarded a lot of data; wrapping those pixels in a lossless format means storing every one of them again in full, including the compression artefacts. PNG is for graphics, screenshots and anything needing transparency — not for photographs.