After 30 years of Deflate, PDFs are finally upgrading. Brotli will soon enter the PDF spec, delivering 15–25% smaller files with zero quality loss, using web-proven compression.
After 30 years of Deflate, PDFs are finally upgrading. Brotli will soon enter the PDF spec, delivering 15–25% smaller files with zero quality loss, using web-proven compression.
Want to make your PDFs 20% smaller for free?
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.
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