PSD to JXL Converter

Encoding: the PSD uses raw or RLE (PackBits) channel data, ZIP in some 16 and 32-bit files; 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: 8, 16 or 32 bits per channel in the PSD; JXL allows 8 to 16 bits per channel, or floating point, and the JXL written here has 8 bits per channel. 16 and 32-bit documents are reduced to 8 bits per channel.

Colour: RGB, CMYK, Lab, greyscale, indexed or multichannel in the PSD; JXL supports sRGB, Display P3, linear and other spaces described in the codestream, written here as 8-bit sRGB.

Transparency: the PSD stores it as transparent layers plus extra alpha channels; the JXL keeps it as an extra channel in the codestream.

Other images: the PSD can hold layers, masks, adjustment layers and smart objects; only the main image is converted.

Metadata: the PSD can carry XMP, EXIF, IPTC and ICC in image resource blocks; JXL can carry EXIF and XMP boxes in the container form, often stripped by encoders, but nothing is copied across.

PSD is Adobe Photoshop's layered working format. It keeps layers, masks and effects, but almost nothing outside Photoshop can display it, so finished designs are exported to PNG or JPG.

A PSD has five sections: a header ('8BPS', channel count, size, depth, colour mode), colour mode data, image resources (thumbnail, ICC, XMP, resolution), layer and mask information, and finally the merged composite image that the Maximize Compatibility option saves.

PSD files usually come from Photoshop and apps that save Photoshop documents, such as Affinity Photo, GIMP, Photopea and Krita.

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 PSD suits editing in Photoshop.

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.