OptiSqueezeby Qanen

PNG Tool

Compress PNG losslessly — pixel-perfect, private

PNG is the format for graphics that must stay exact: logos, screenshots, UI shots, line art and anything with transparency. This page re-encodes PNGs with a WebAssembly port of UPNG — fully lossless, entirely on your device.

Drop an image anywhere, or browse files

Supports WebP, JPEG, PNG, and AVIF up to 50MB. Processed offline.

Lossless means lossless

The Lossless preset on this page decodes and re-encodes your PNG so that every pixel of the output is identical to the input — only the file size changes. That makes it safe for:

  • Screenshots and UI assets where text edges and flat colour bands must stay crisp.
  • Logos and icons with alpha transparency.
  • Master files you may edit again later — no generation loss.

When to pick a different format

For photographs, lossless PNG keeps a lot of data your eyes would never miss — a WebP at quality 82 or an AVIF will be many times smaller at visually identical quality (the trade-offs are laid out in WebP vs AVIF vs JPEG). Keep PNG for the graphics that genuinely need it, and convert photos instead.

Re-encoding also strips ancillary metadata chunks, which shrinks the file a little more and removes embedded details — see stripping EXIF metadata.

PNG questions

No. Lossless encoding reproduces the original pixels exactly — mathematically identical output, smaller container. That is what the Lossless preset (quality 100) does here, using the UPNG WebAssembly codec.
PNG stores photographic data very faithfully, so lossless savings on photos are modest. If the image is a photo rather than a graphic, converting it to WebP or AVIF will shrink it far more — visually losslessly, if not byte-exactly.
Yes — alpha transparency is one of PNG’s core strengths, and it survives lossless compression untouched. JPEG has no transparency channel at all.
Yes. The UPNG codec downloads to your browser once, then runs locally (and keeps working offline). No image bytes are transmitted anywhere.

Need a different format? Compare them all in WebP vs AVIF vs JPEG or go back to the main compressor.

Other formats

WebP compressorAVIF compressorJPEG compressor

Related guides

WebP vs AVIF vs JPEG: which image format should you use?A practical comparison of WebP, AVIF and JPEG — file size, quality, transparency and browser support — with a simple rule of thumb for choosing the right image format.How to compress images online without uploading themMost online image compressors upload your files to their servers. Here's how in-browser (client-side) compression keeps sensitive photos on your device — and when it matters.