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Convert image format

Free, in your browser — pick a format pair below. Your image never leaves your device.

AVIF to JPG

Free, in your browser — your AVIF never leaves you. Transparent areas become white.

AVIF to PNG

Free, in your browser — your image never leaves you. Transparency is preserved.

AVIF to WebP

Free, in your browser — your image never leaves you. Alpha channel preserved.

JPG to AVIF

Free, in your browser — your JPG never leaves you. AVIF files are 40-60% smaller than JPG.

JPG to PNG

Free, in your browser — your image never leaves you. PNG is lossless; the file size grows.

JPG to WebP

Free, in your browser — your image never leaves you. WebP files are 25–34% smaller.

PNG to AVIF

In your browser — no upload, no signup. Alpha transparency preserved. First encode: ~1 s.

PNG to JPG

Free, in your browser — your image never leaves you. Transparent areas become white.

PNG to WebP

Free, in your browser — transparency kept, file gets smaller, nothing is uploaded.

WebP to AVIF

Free, in your browser — your image never leaves you. Alpha transparency is preserved.

WebP to JPG

Free, in your browser — your image never leaves you. Transparent areas become white.

WebP to PNG

Free, in your browser — no upload. Transparency preserved. Your PNG will be larger than the WebP.

RoundCut's image converter changes an image's format — PNG, JPG, WebP, or AVIF — in your browser. Pick a pair below. The file never leaves your device: no upload, no server, no signup. Encode is native HTML canvas (PNG/JPG/WebP) or a WASM AVIF encoder. Free.

How does the image converter work?

Pick a format pair below (for example, PNG to JPG) and you go straight to that pair's page. Drop a file there and the conversion runs the moment the file lands — no "Convert" button to chase. The encode happens locally: PNG, JPG, and WebP go through the browser's native canvas; AVIF runs through a WebAssembly encoder fetched only when you ask for AVIF. When the result is ready, the Download button saves the new file to your device. Nothing is queued on a server.

Which formats can I convert?

The engine handles PNG, JPG, WebP, and AVIF as both input and output. GIF files can be converted FROM (first frame only) — but GIF output is not supported in the browser. As more pairs ship to RoundCut, they appear in the picker above automatically. If a pair you need is not listed yet, it means we have not finished its dedicated page; the engine can already handle it, the SEO copy is just queued.

Does conversion change image quality?

It depends on the target format. PNG output is lossless — pixels are preserved byte-for-byte. JPG, WebP, and AVIF use lossy compression tuned to a near-lossless quality setting (about 43 dB PSNR for photographs — visually indistinguishable from the source). Converting a photo PNG to JPG gives you a smaller file with subtle, imperceptible artifacts. Converting a JPG back to PNG produces a larger file: lossless re-encoding of an already-lossy source does not recover the data that was discarded the first time.

Is it safe? Does my image get uploaded?

Your file never leaves your browser. The conversion runs entirely on your device using the platform image engine (canvas) or a local WebAssembly module (AVIF). You can verify it with DevTools open: zero outbound image requests during conversion. Compare that to typical online converters, which advertise "secure HTTPS upload" — the file still goes to a server. With RoundCut, there is no server in the path at all, so there is nothing to upload, nothing to log, nothing to delete after 24 hours.

When should I convert my image format?

Three common reasons: photography (use JPG or AVIF for smaller files on the web), graphics and logos (use PNG or WebP for lossless quality with transparency), and social or platform requirements (some platforms accept only specific formats). Convert PNG to JPG when transparency is not needed and file size matters. Convert JPG to PNG when you need to preserve the current image without further loss for editing. Convert to WebP or AVIF when page-load speed matters and your audience uses modern browsers.

Frequently asked questions

Does my image get uploaded to a server?

No. The entire conversion happens in your browser via HTML canvas (for PNG, JPG, and WebP) or a local WebAssembly AVIF encoder. There are zero outbound image requests — you can verify it with DevTools Network tab open while you convert. No server in the path means no logging, no storage, no "deleted after 24 hours" promise to trust.

Which image formats can I convert?

PNG, JPG, WebP, and AVIF — both as inputs and outputs. GIF files can be used as inputs (first frame only), but GIF output is not supported in the browser. The format-pair grid above shows the pairs that have a dedicated page today; more pairs ship over time.

Is the conversion free? Are there limits?

Fully free. No signup, no watermark, no daily limit. The only real limit is your browser's memory budget — roughly 25 MB of source image on mobile Safari and around 100 MB on desktop. There is no server quota because nothing is sent to a server.

Does converting reduce image quality?

It depends on the target format. PNG output is lossless — no quality loss. JPG, WebP, and AVIF are lossy encoders set to a near-lossless quality (about 43 dB PSNR for photographs — visually indistinguishable from the source). Converting a lossless source to JPG produces a smaller file with subtle artifacts. Converting a JPG to PNG produces a larger file — lossless re-encoding of a lossy source does not recover discarded data.

What happens to transparent areas when I convert to JPG?

JPG has no alpha channel, so every transparent pixel must be replaced by a solid color. The conversion fills transparency with white. If you need a different background color, paint it onto the source image in an editor before converting. Converting to PNG, WebP, or AVIF preserves transparency.

Can I convert multiple images at once?

Not yet — the current version converts one file at a time. Batch conversion is planned for a future release.