The Image Format Converter reads almost any image you have and saves it as one of the four formats the web and most apps use today: JPG, PNG, WebP or AVIF. It opens JPG, PNG, WebP, AVIF, HEIC and HEIF photos from iPhones, GIF, BMP, TIFF, SVG, ICO and Photoshop PSD files. Pick the output, and the tool decodes each file, draws it on a canvas and encodes it again, all inside your browser tab.
You control the result. A quality slider (10 to 100%) sets the trade-off between size and detail for JPG, WebP and AVIF. WebP also has a lossless mode for logos and screenshots. When the output is JPG, which has no transparency, you choose the colour that fills transparent areas. Optional max width and height scale large images down while keeping their proportions, and before you spend a run the tool shows the expected file size of your first image.
Some limits are worth knowing. Animated GIFs and WebPs become a still image of the first frame, multi-page TIFFs give the first page, and PSDs are converted from the flattened image Photoshop stores in the file, so layers are merged. Images above about 16.7 megapixels are scaled down to fit the browser's canvas limit, and camera metadata such as EXIF date and GPS location is not copied to the new file. AVIF encoding is slow in a browser and can take several seconds per photo.