TIFF to JXL Converter

Encoding: the TIFF uses none, LZW, PackBits, Deflate or JPEG, chosen per file; JXL uses lossy VarDCT or lossless modular coding; existing JPEGs can be repacked without loss, and the download is a JPEG XL encoded with libjxl compiled to WebAssembly, lossy at the quality you choose or lossless.

Bit depth: 1 to 16 bits per channel, or 32-bit floating point in the TIFF; JXL allows 8 to 16 bits per channel, or floating point, and the JXL written here has 8 bits per channel. 16-bit and floating-point TIFFs are reduced to 8 bits per channel.

Colour: RGB, CMYK, Lab, greyscale or palette, often with an ICC profile in the TIFF; JXL supports sRGB, Display P3, linear and other spaces described in the codestream, written here as 8-bit sRGB.

Transparency: the TIFF stores it as an extra sample declared in the ExtraSamples tag; the JXL keeps it as an extra channel in the codestream.

Other images: the TIFF can hold several pages, each in its own image file directory; only the main image is converted.

Metadata: the TIFF can carry EXIF, XMP, IPTC and ICC, all stored as tags; JXL can carry EXIF and XMP boxes in the container form, often stripped by encoders, but nothing is copied across.

TIFF is the professional archive and print format. It can hold multiple pages, high bit depths and lossless data, and is common in scanning, publishing and GIS.

A TIFF begins with 'II' or 'MM' for the byte order and the number 42, then an offset to the first image file directory (IFD): a table of tags giving the size, compression, colour model and the location of the strips or tiles of pixels. Each further page is another IFD.

TIFF files usually come from scanners, print and publishing workflows, photo archives and tethered camera capture.

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 is the better choice for archiving and future-proof high quality storage, while TIFF suits printing, scanning and archival masters.

JXL strengths: Excellent lossy and lossless compression; Progressive decoding and HDR; Huge image sizes. Drawbacks to weigh: Browser support is limited (Safari only by default); Few apps can open it yet.