Ask an image converter for AVIF in a browser that cannot write AVIF, and you need a plan for what happens next. The conversion runs on the canvas of your own browser, so the browser decides which formats it can encode. AVIF and BMP are the formats most likely to fail.
When the browser cannot write AVIF or BMP
When the browser cannot encode the format you asked for, it hands back PNG data. The tool checks the type of the result. It then saves the file with the extension .png and shows a message that names the format your browser could not write. If you need AVIF or BMP, try another browser, or convert to WebP, PNG or JPG instead.
Using the image converter: five steps from drop to download
- Drop an image on the drop zone or click it to choose a file. The preview shows the file name, the size and the pixel dimensions.
- Open Target format and pick WebP (the default), PNG, JPG / JPEG, AVIF or BMP.
- For WebP, JPG and AVIF, move the Quality slider. It runs from 10% to 100% and starts at 90%. PNG and BMP hide it.
- Press Convert & Download Now. The file keeps its old name with the new extension, and a message shows the new size.
- Press Choose another image to start over.
Picking a format for the job
- WebP for pictures on a web page. A 6 MB PNG screenshot can drop to a few hundred KB.
- JPG when an upload form or an old program accepts nothing else.
- PNG if the picture needs transparency, or if you want no loss from the conversion itself.
Going back does not repair anything. A JPG saved as PNG keeps every flaw of the JPG, and the file gets larger.
White fill, one frame, no metadata
JPG and BMP cannot store transparency, so the tool paints a white background first. PNG, WebP and AVIF keep transparent areas. An animated GIF gives one frame. An SVG is drawn at its own width and height. The tool handles one image at a time and keeps the pixel size, so it neither resizes nor crops.
The new file is drawn fresh, so metadata such as the camera model or the GPS position is not copied. A very large image can exceed the canvas limit of the browser. You then see the message Conversion failed.
What happens to the picture
The browser reads the file into memory, draws it on a canvas and builds the new file there. Pressing the button sends no request. You can check this in the network panel of the developer tools. The result is a normal download, and the clipboard is not used.