Convert image format

How image format conversion works

Drop an image, the tool shows its format and you pick what to convert it to. The image is decoded onto a canvas and re-encoded, all in your browser, with nothing sent to a server. It handles up to ten files at once.

It opens JPG, PNG, WebP, GIF, BMP, AVIF, ICO, TIFF, HEIC from an iPhone and SVG. It writes these formats:

• JPG: photos. The smallest files, but no transparency.
• PNG: logos, screenshots, images with a transparent background. Lossless, but larger.
• WebP: the modern web format. Smaller than both JPG and PNG, and it handles transparency.
• AVIF: even smaller than WebP, and every current browser opens it. The encoder is about 3.5 MB and downloads on the first conversion.
• GIF: 256 colours only, good for simple graphics. An animated GIF on the input keeps its first frame.
• BMP: uncompressed, for older Windows software.
• TIFF: print and archiving, lossless with deflate compression.
• ICO: an icon for the web or Windows. The image is fitted into a square of the chosen size, up to 256 px.

When you convert an image with a transparent background to JPG or BMP, the transparency is lost. The tool spots that in advance, warns you and lets you pick the colour the background is filled with. Without that, the transparent areas would come out black.

Frequently asked questions

How do I convert PNG to JPG without a black background?

That is exactly what the background colour picker is for. Leave it white, or choose the colour the image will sit on.

Is WebP better than JPG?

For the web, yes. At the same quality it tends to be 25–35% smaller. For print or older software, JPG is the safer bet.

Does it open HEIC files from an iPhone?

Yes, HEIC and HEIF are unpacked by a decoder right in the browser. It downloads the first time you drop such a file.

Why does GIF or TIFF download a processing core?

Browsers cannot write those formats themselves, so ffmpeg compiled to WebAssembly handles them. The core is about 32 MB, downloads once and every later conversion runs without waiting.

Do the dimensions change?

No, the dimensions stay. The exception is ICO, where the image is scaled down to the chosen icon size. Otherwise only the format and the amount of compression change.