Brotli Compression in PDF
BuildVu, FormVu, and JPedal already read Brotli-compressed streams, ahead of the PDF Association's new PDF 2.0 specification
The PDF Association's Technical Working Group has introduced Brotli compression specification for PDF 2.0 as an option. As active members of the working groups, we have been involved in the whole process and ahead of the game with support for reading in our May/June 2026 releases and writing due to ship later in 2026.
Why introduce Brotli to the PDF specification?
PDF has used Deflate/zlib compression since PDF 1.0. Brotli offers significant improvements to file sizes on most PDF files, particularly on text-heavy content like fonts and page content streams. The new PDF 2.0 provision adds the option to use Brotli instead of Deflate for smaller file sizes.
Current Brotli Support Across Our Products
| Product | Supports reading Brotli compressed data | Since | Release notes |
|---|---|---|---|
| JPedal | ✅ Yes | 2026.05 (27 May 2026) | 2026.05 release notes |
| BuildVu | ✅ Yes | 2026.06 (23rd June 2026) | 2026.06 release notes |
| FormVu | ✅ Yes | 2026.06 (23rd June 2026) | 2026.06 release notes |
A PDF containing Brotli-compressed streams opens, renders, and converts normally in all three products. No configuration is required.
Brotli Writing: Coming later in 2026
JPedal: write Brotli-compressed PDFs
JPedal's PDF Manipulator adds an option to use Brotli as another target compression scheme alongside the ones it already supports.
BuildVu and FormVu: smaller web fonts
WOFF2 fonts support the use of Brotli compression for smaller files. Once BuildVu and FormVu apply the same compression to the fonts they embed, converted HTML5 output gets the option for smaller files with no changes needed.
Pure Java, No Third-Party Code
As with AVIF, HEIC, and WebP, Brotli support across all three products is written from scratch in pure Java rather than wrapping an external library. This allows for in-depth integration and optimisation, and removes a potential third-party security vulnerability.
Frequently asked questions
What is Brotli compression in PDF?
Brotli is a compression algorithm originally built for the web (it is also used in WOFF2 web fonts) that generally compresses better than the Deflate/zlib compression PDF has used since PDF 1.0.
What are the benefits of using Brotli in PDF?
Smaller files than Deflate/zlib, especially for fonts and page content streams, using an algorithm already proven on most of the web’s HTTP traffic and every WOFF2 font.
What are the disadvantages of using Brotli in PDF?
Encoding costs more CPU time than Deflate (decoding is still fast). It’s a new (and optional) PDF 2.0 feature, so it can only be used if your users are using tools which support it.
Do BuildVu, FormVu, and JPedal support Brotli-compressed PDFs?
All three products read PDFs containing Brotli-compressed streams. JPedal added this in its 2026.05 release; BuildVu and FormVu followed in 2026.06.
Can BuildVu, FormVu, or JPedal write Brotli-compressed PDFs?
In a later 2026 release we will add support for writing out brotli encoded data. JPedal’s PDF Manipulator will be able to convert PDFs to Brotli compression, and BuildVu and FormVu will use Brotli to shrink the web fonts embedded in their HTML5 output.
Is IDRsolutions' Brotli support pure Java?
Our implementation is pure Java 17 code with no JNI, no native Brotli library, no separate binary to install. It ships inside the same JAR as the rest of the product.