JXL to GIF Converter

Encoding: the JXL uses lossy VarDCT or lossless modular coding; existing JPEGs can be repacked without loss; GIF uses lossless LZW over a palette of at most 256 colours, and the download is a GIF with an optimised palette of up to 256 colours per frame, dithered.

Bit depth: 8 to 16 bits per channel, or floating point in the JXL; GIF allows 8 bits per pixel, as indexes into a palette, and the GIF written here has 8 bits per pixel (palette). High-bit-depth JPEG XL files are reduced to 8 bits per channel.

Colour: sRGB, Display P3, linear and other spaces described in the codestream in the JXL; GIF supports an indexed palette of up to 256 colours per frame, written here as an indexed palette of up to 256 colours.

Transparency: the JXL stores it as an extra channel in the codestream; the GIF keeps it as on or off per pixel, so soft edges become hard.

Animation: frames inside a single codestream; the GIF keeps every frame and its timing, as image blocks with their own delay and disposal method, looped by the NETSCAPE2.0 extension.

Metadata: the JXL can carry EXIF and XMP boxes in the container form, often stripped by encoders; GIF can carry comment and application extension blocks, but no EXIF, but nothing is copied across.

JPEG XL is a next-generation format designed to replace JPEG. It compresses better than JPEG and WebP, supports lossless, HDR and progressive decoding, and can losslessly repack existing JPEGs.

A JPEG XL file is either a bare codestream starting with FF 0A or an ISO base media container whose 'jxlc' box holds the codestream. A recompressed JPEG keeps a 'jbrd' box that lets the original JPEG bytes be rebuilt exactly.

JXL files usually come from image editors, archival pipelines and lossless JPEG recompression.

GIF is the classic animated image format. It is limited to 256 colours per frame and 1-bit transparency, so photos look grainy and files are large, but it plays everywhere.

A GIF starts with 'GIF89a' (or the older 87a), a logical screen descriptor and an optional global colour table, then image blocks, each preceded by a graphic control extension that sets its delay and transparent colour.

GIF is the better choice for short animations and reactions that must play everywhere, while JXL suits archiving and future-proof high quality storage.

GIF strengths: Animation that works everywhere; Simple, universally supported; Good for small flat graphics. Drawbacks to weigh: Only 256 colours per frame; Hard-edged transparency only; Large files for photos or long clips.