ISO PDF spec is getting Brotli – ~20 % smaller documents with no quality loss

Summary

For nearly three decades; or November 1996 to be exact, PDFs have relied on Deflate—the same compression algorithm that powers your ZIP files. Meanwhile, the web moved on. In 2015, Google introduced Brotli, a compression algorithm so efficient it now powers 95% of internet traffic. Websites got faster. Downloads got smaller. CDNs got cheaper. Now PDFs are getting the same upgrade. The PDF Association is bringing this battle-tested web compression technology into the PDF specification itself. After a decade of Brotli proving its worth across billions of web requests daily, it's now getting ready to make it's introduction into ISO 32000. With iText, we can help drive widespread adoption with a production-ready Brotli encoder and decoder for the PDF ecosystem. The result? 15-25% smaller files with zero quality loss, using the same algorithm trusted by Google, Cloudflare, and every major CDN. Why PDF compression has struggled to evolve PDF compression has been stuck in 1996 for a good reason: backward compatibility is sacred. The PDF Association operates under a strict principle—any new feature must work seamlessly with existing readers, or it risks fragmenting the ecosystem. Adding a new compression algorithm isn't just a technical change; it's a breaking change that could render documents unreadable in older software. This creates a high barrier for innovation. Beyond compatibility concerns, there are other practical challenges. The PDF specification moves slowly by design—it's an ISO standard that requires consensus by hundreds of stakeholders. Compression algorithms must be royalty-free (ruling out patented options), widely supported across platforms, and battle-tested in production. Finally, the ecosystem is conservative: enterprises and governments rely on PDFs for archival and legal documents that must remain accessible for decades, making any breaking change a risk that needs extraordinary justification. Encoding and decoding: Technical implementation To get Bro...