Free, in your browser — your JPG never leaves you. AVIF files are 40-60% smaller than JPG.
or drop the image here
Converting…
RoundCut converts JPG to AVIF entirely in your browser using a WebAssembly encoder (no upload, no server). AVIF is a lossy modern format — output is visually indistinguishable from the source at default settings, but not bit-for-bit identical. Real photos typically come out 40 to 60 percent smaller than the original JPG.
Drop a JPG file on the upload area (or click to pick one). The conversion runs the moment the file lands — there is no "Convert" button to chase. The first AVIF encode of a session loads a small WebAssembly module (~1 second the first time, instant after); small photos finish in a fraction of a second, large ones in a few seconds. When the result is ready, the Download button saves the AVIF to your device with the same name and the new extension.
AVIF is supported by 94 percent of browsers globally as of 2026. Chrome (since version 85), Firefox (since 93), Edge (since 121), and Safari on iOS 16+ and macOS Ventura+ all decode AVIF natively. Older iPhones on iOS 15 or earlier do not — and neither does Internet Explorer or pre-2022 Android browsers. If you need to reach those visitors, serve a JPG or WebP fallback alongside the AVIF using the HTML
Keep JPG for legacy systems, email attachments, CMS uploads that downstream tools may re-process, and any pipeline that pre-dates 2022. Switch to AVIF for modern websites where page-load speed matters: hero photos, gallery images, and anything served behind a CDN that supports content negotiation. AVIF wins on file size at the same visual quality; JPG wins on universal compatibility and editor support. Most production sites today serve AVIF with a JPG fallback via the
In our measured tests, a typical 17 KB JPG (1024×768) came out as a 6 KB AVIF — 64 percent smaller. A 116 KB photo (3840×2160) became 16 KB — 86 percent smaller. The realistic range on real photos is 40 to 86 percent smaller, depending on detail and noise. Smoother content (skies, skin) compresses harder; busy textures less so. Quality is fixed at q85 — calibrated for photography, with a PSNR around 42 dB. Visually indistinguishable from the source, but not bit-for-bit identical.
The conversion runs entirely in your browser via WebAssembly. Nothing is uploaded, nothing is logged, nothing is queued on a server. If you open DevTools and watch the Network panel while you convert, you will see zero outbound image requests after the encoder module loads on first use. No account, no watermark, no daily limit beyond what your device's memory can hold. The same code path runs on every browser — there is no server fallback waiting in the wings.
Yes, technically — AVIF is a lossy format, and JPG is already lossy. The conversion encodes at q85 (a near-lossless setting tuned for photos, PSNR around 42 dB), so the result is visually indistinguishable from the source JPG to the naked eye, but it is not bit-for-bit identical. For web publishing this is invisible. For archival masters, keep the original JPG (or, better, the original RAW).
Yes — on iPhone with iOS 16 or later (released September 2022). Safari 16.4+ on iOS and macOS Ventura+ both decode AVIF natively. iPhones still on iOS 15 or earlier do not support it; for those visitors, serve a JPG or WebP fallback through the HTML
On real photos, expect 40 to 86 percent smaller. In our measured tests: a 17 KB JPG became a 6 KB AVIF (64 percent smaller); a 116 KB photo became 16 KB (86 percent smaller). The exact ratio depends on content — smooth areas like sky and skin compress aggressively; busy textures like foliage or grain compress less. Quality is held constant at q85.
Yes — your file never leaves your device. The AVIF encoder runs locally in your browser via WebAssembly. Open DevTools, switch to the Network tab, and convert a file: you will see zero outbound image requests after the encoder module is fetched once on first use. No server processing, no temporary storage, no account.
AVIF reaches roughly 94 percent of browsers worldwide. Chrome 85+, Firefox 93+, Safari 16.4+ (iOS 16+ / macOS Ventura+), and Edge 121+ all decode it natively. The remaining 6 percent are older browsers, iOS 15 or earlier, and Internet Explorer. For full coverage, serve a JPG or WebP fallback alongside the AVIF using the HTML
This tool encodes at q85 — a near-lossless setting calibrated for photography. The resulting PSNR is around 42 dB, which is visually indistinguishable from the source for most viewing conditions. Lower quality (q60-75) would shrink files further at some visible cost; higher quality approaches lossless but loses most of AVIF's size advantage. q85 is the sweet spot we ship.