Brotli Browser Support — Can I Use br Encoding?

Brotli Browser Support

Brotli compression has reached near-universal browser support, making it safe to use as the primary compression algorithm with gzip as a fallback.

Current Browser Support (2025)

Browser	Brotli Support	Since Version
Chrome	Yes	v49 (2016)
Firefox	Yes	v44 (2016)
Safari	Yes	v11 (2017)
Edge	Yes	v15 (2017)
Opera	Yes	v36 (2016)
Samsung Internet	Yes	v5 (2017)
IE 11	No	N/A
Opera Mini	No	N/A

Global Support: 97%+

According to Can I Use data, Brotli is supported by over 97% of global browser traffic. The remaining 3% consists primarily of IE 11 and very old mobile browsers.

Implementing Brotli with Gzip Fallback

The standard approach is to serve both:

# nginx configuration
brotli on;
brotli_types text/html text/css application/javascript application/json;
gzip on;
gzip_types text/html text/css application/javascript application/json;

The server checks the Accept-Encoding header and selects the best supported encoding:

1. If br is in Accept-Encoding → serve Brotli
2. Else if gzip is in Accept-Encoding → serve gzip
3. Else → serve uncompressed

HTTPS Requirement

Browsers only accept Brotli over HTTPS. This is a security measure, not a technical limitation of the algorithm. On HTTP connections, gzip is the maximum available compression.

Pre-compressed Static Files

For static assets, generate both .br and .gz files at build time:

# Generate both formats
brotli -o bundle.js.br bundle.js
gzip -k bundle.js

Most web servers and CDNs can automatically serve the pre-compressed version when the client supports it.