Convert image

Turn JPG, PNG, WebP, GIF, BMP, TIFF or AVIF into JPG, PNG, WebP or AVIF — right in your browser, no upload.

How to convert an image

  1. Drop or pick a JPG, PNG, WebP, GIF, BMP, TIFF or AVIF file.
  2. Choose the target format — JPG, PNG, WebP or AVIF — and tune the quality if you like.
  3. Convert, compare before/after, and download — all on your device. Animated GIFs are split into one image per frame, packed as a ZIP.

Why convert images?

Modern formats like WebP and AVIF cut file sizes dramatically at the same visual quality — faster pages, better Core Web Vitals, lower bandwidth. Converting the other way matters too: JPG opens everywhere, and PNG keeps exact pixels and transparency. OptImg runs the same Rust codecs desktop tools use, compiled to WebAssembly, so you get desktop-grade output without uploading anything or waiting in a queue.

Frequently asked questions

Are my images uploaded to a server?
No. Conversion runs entirely in your browser with WebAssembly — your image never leaves your device, there is no queue, and no size limit beyond your device's memory.
Which format should I convert to?
WebP is the best default for the web: much smaller than JPG or PNG with wide browser support. AVIF is smaller still but slower to create. Choose JPG for maximum compatibility with older software, and PNG when you need pixel-perfect lossless output with transparency.
What happens to an animated GIF?
Each frame is extracted and converted to a separate image in your chosen format, then delivered together as a ZIP — the same behavior as classic GIF-to-JPG converters. Animated WebP/AVIF output isn't supported yet.
What happens to transparency when converting to JPG?
JPG has no alpha channel, so transparent areas are flattened onto a white background. PNG, WebP and AVIF outputs keep transparency intact.
Why is AVIF slower than the other formats?
AVIF uses the AV1 video codec, which trades encode time for the smallest files. Small images finish in a moment; very large photos can take a minute or more — the tool warns you beforehand and you can cancel anytime.
Does converting reduce image quality?
PNG output is lossless. JPG, WebP and AVIF are lossy, tuned to visually transparent defaults (JPG 82, WebP 80, AVIF 60) — and the quality slider is yours. If a conversion can't produce a smaller file than your original, we hand your original back instead.