[Feature]: Brotli compression coming to PDF

[JanSlabon]

Is the feature relevant to the Firefox PDF Viewer?

Yes

Feature description

The PDF Association is planing to add Brotli compression to PDF 2.0: https://pdfa.org/brotli-compression-coming-to-pdf/ (here you will also find some example documents)

Several talks at the PDF Days 2025 in Berlin notice this breaking change and all vendors were pleased to implement this as early as possible so that this new feature can be introduced with less problems as possible.

Brotli is already available in JS world: https://github.com/google/brotli/tree/master/js

The formal technical specification for the new Brotli filter is almost ready for review and it will be made available soon.

At the end the implementation will be the same as FlateDecode but the data are simply handled by compress/decompress methods of the Brotli library.

Other PDF viewers

No response

[robinwatts]

In case it is helpful, both MuPDF and Ghostscript include support for reading/writing such files, and their source is available as exemplars.