Compress PNG — lossless optimization, done locally
PNG compression has room for improvement more often than you would think: many tools write PNGs quickly rather than optimally, leaving bytes on the table. This optimizer re-encodes your PNGs with an oxipng-based encoder compiled to WebAssembly, searching for a more efficient encoding of the exact same pixels — the output is still a perfect, lossless PNG. Set expectations honestly: gains vary a lot. Poorly optimized files can shed a meaningful chunk of their size, while already-optimized PNGs may barely change. If you need aggressive reductions, a lossy format like WebP or AVIF is the tool for that job. Either way, your files are processed on your device and never uploaded.
How it works
- Drop .png files below — whole batches at once are fine.
- The optimizer re-encodes each file losslessly; no settings needed.
- Compare the before/after sizes and download the results.
Frequently asked questions
How much smaller will my PNGs get?
Honestly: it varies. Files saved by quick exporters often shrink 10–40%; PNGs that were already run through an optimizer may improve by only a few percent, or not at all. Lossless optimization can only remove encoding inefficiency, not image data.
Is any quality lost?
None. This is lossless recompression — the optimized PNG decodes to pixels identical to the original. Only the way those pixels are encoded inside the file changes.
What if I need bigger savings than this gives me?
Switch formats rather than squeezing PNG harder. Converting to lossy WebP or AVIF typically cuts far more — often 70%+ for screenshots and photos — at the cost of no longer being pixel-exact. We have PNG to WebP and PNG to AVIF tools for that.
Are my files uploaded to be compressed?
No — the oxipng-based encoder runs entirely in your browser via WebAssembly. Your PNGs stay in local memory, and the optimizer works offline once the page has loaded.