Image Format Converter
Convert images between popular formats instantly. JPG, PNG, WebP, and AVIF formats supported in any conversion direction. Batch conversion with automatic ZIP download. Control quality settings for lossy formats and preserve transparency where supported. Everything runs in your browser — images are never uploaded to any server.
What does this tool do?
The Image Converter transforms images between four major web and print formats. Convert JPG to PNG for transparency support, PNG to JPG for smaller file sizes, or to modern WebP/AVIF for superior compression. Batch processing handles multiple files at once with individual quality controls. Transparency is preserved when converting to formats that support it (PNG, WebP, AVIF) — note that JPG does not support transparency. All conversions use high-quality resampling and professional encoding libraries.
How it works
Using browser-based image processing with WebAssembly codecs, the tool decodes source images using appropriate libraries (libjpeg-turbo for JPEG, libpng for PNG, libwebp for WebP, libavif for AVIF). The decoded bitmap is then encoded to the target format using the selected quality settings. For transparency: PNG and WebP preserve alpha channels fully; AVIF supports alpha but default encoding may use YUV 4:2:0 which can soften edges; JPEG discards alpha entirely (transparent areas become filled, typically white). Quality settings apply only to lossy formats (JPEG, WebP, AVIF); PNG output uses lossless compression regardless. Processing runs in Web Workers for responsive UI.
Features
- All 4 formats both directions: JPEG ↔ PNG ↔ WebP ↔ AVIF
- Batch conversion with one zip download
- Quality slider for lossy outputs (JPEG/WebP/AVIF)
- Lossless PNG via oxipng
- Transparency preservation where supported
- Web Worker — main thread stays responsive
- 100% in-browser — no server uploads
How to use
- 1
Drop images
Any combination of JPEG, PNG, WebP, AVIF — even mixed batches of different formats.
- 2
Pick output format
WebP for web (broad support, ~25% smaller than JPEG). AVIF for newer browsers (~50% smaller). PNG for lossless/archival. JPEG for maximum compatibility.
- 3
Set quality (lossy formats)
80-90 is usually good for WebP/AVIF. PNG quality slider has no effect — PNG is always lossless.
- 4
Convert
Output downloads as a zip if you've dropped multiple files. Individual download for single files.
Common use cases
Web format optimization
Convert images to WebP or AVIF for modern browsers with fallbacks, reducing page weight and improving load times.
Transparency needs
Convert JPG to PNG when you need transparent backgrounds for logos, icons, or overlay graphics.
Compatibility conversion
Convert newer formats (WebP, AVIF) to JPEG for older systems, email clients, or software with limited format support.
Print preparation
Convert to high-quality PNG or TIFF-equivalent for print workflows that require lossless or specific formats.
Tips & best practices
- WebP: universal modern browser support (Chrome, Firefox, Safari, Edge). Use as default for web compression
- AVIF: best compression but slower to encode. Safari support added in 16.4. Consider AVIF with WebP fallback
- PNG transparency is preserved perfectly. WebP transparency is also lossless. AVIF alpha can be lossy depending on encoding settings
- JPEG has no alpha channel — converting transparent PNG to JPEG fills transparent areas (usually white). Plan accordingly