SizeMint tools
Convert images to JPG, PNG, WebP or AVIF.
Drop your images — SizeMint detects each file's real format and recommends the best output. Everything happens in your browser.
Drop images here
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JPG, PNG, WebP, AVIF, GIF or BMP · multiple files supported · up to 25 MB eachQuality applies to JPG, WebP and AVIF. PNG output is lossless, so the slider has no effect on it.
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Converted images
The suite
More image tools, same privacy.
Every tool runs entirely in your browser.
How it works
Real format detection, honest recommendations
SizeMint reads each file's signature bytes — not just its extension — so a PNG renamed to .jpg is still detected as PNG. Based on what it finds, the tool recommends the output format that makes the most sense: WebP for most photos and screenshots, JPG for maximum compatibility, PNG when you need lossless quality or transparency.
What about transparency?
WebP and PNG preserve transparent areas. JPG has no transparency support, so transparent pixels are filled white during conversion. AVIF output appears automatically when your browser can encode it.
Private by design
Detection, decoding and encoding all use local browser APIs. Your images never leave your device — see the Privacy Policy for the current disclosures.
FAQ
Questions about converting image formats
Which image formats can I convert between?
You can convert between JPG, PNG, WebP and AVIF. GIF and BMP inputs are converted from their decoded image; animation is not preserved.
Does converting an image reduce its quality?
Converting to a lossy format (JPG, WebP, AVIF) re-encodes the image at your chosen quality. PNG output is lossless.
Will converting PNG to WebP keep transparency?
Yes. WebP supports transparency and SizeMint preserves the alpha channel. JPG does not support transparency, so transparent areas become white.
Are my images uploaded anywhere during conversion?
No. Format detection, decoding and encoding all happen in your browser using local APIs.