Convert PNG to AVIF — with transparency, without uploading
For web developers sitting on folders of heavyweight PNGs, AVIF is usually the biggest single size win available. The AV1-based format compresses far beyond what PNG can manage and — crucially for anyone converting PNGs — it supports full alpha transparency, so hero images, illustrations, and cut-outs keep their transparent backgrounds. The encoder here is compiled to WebAssembly and runs in your browser tab: your assets are never uploaded, there are no per-image fees, and batch mode lets you convert an entire directory’s worth at once. Encoding is CPU-intensive by nature, so give big images a few seconds; the savings are worth the wait.
How it works
- Drop .png files below, singly or in bulk.
- Adjust the quality slider — even moderate settings look clean in AVIF.
- Save each .avif output and compare file sizes.
Frequently asked questions
Does AVIF keep my PNG’s transparency?
Yes. AVIF has full alpha channel support, so transparent and semi-transparent pixels come through intact. This makes it a genuine PNG replacement for the web, unlike JPG.
Is the conversion lossless?
No — this tool produces lossy AVIF at the quality you select, which is where the large size reductions come from. At high quality settings the difference from the PNG is extremely difficult to see. Keep your PNG originals as the editing masters.
What kind of size reduction should I expect?
It depends on content: photographic PNGs and screenshots often shrink by 80–90%, while simple flat graphics shrink less dramatically. Either way AVIF almost always beats both PNG and WebP on size.
Are my design assets uploaded anywhere?
No. Everything — decoding the PNG, encoding the AVIF — happens locally in your browser through WebAssembly. Unreleased designs and client work never leave your machine.