BR file format: what it is and how to use it

A .br file is content compressed with Google's Brotli, the web's best text compressor, built for HTTP and fonts. Learn when to use it and what to choose instead.

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What is a BR file?

A .br file is data compressed with Brotli, the algorithm Google standardized as RFC 7932 in 2016, engineered specifically for web text: HTML, CSS, JavaScript and WOFF2 fonts. A built-in static dictionary of common web strings plus modern context modeling gives it roughly 20–26% better ratios than gzip on text, which is why browsers negotiate br content-encoding and font files use it natively.

When should you use .br?

  • Serving web content: Content-Encoding: br is standard on all modern browsers.
  • Precompressed static assets: .js.br, .css.br files sit next to originals on CDNs.
  • WOFF2 internals: every woff2 font carries Brotli-compressed tables.

When is another format a better fit?

As a user-facing archive, .br is a stream format, not a file container, so ZIP or 7z serves actual sharing. For pipelines and filesystems zstd beats it on speed; for universal readability gzip still wins. Brotli's home is the HTTP layer.

The short version: BR is the web's wire compression: excellent for serving text, but the wrong shape for archives.

How to open a BR file

On Windows

Double-click the file, or open it with 7-Zip (plugin).

On macOS

PeaZip opens BR files on macOS.

In your browser

Open BR files right in a browser tab or with the dexrr viewer. No install, no upload.

Also opens in

  • Any web browser (HTTP content encoding)
  • PeaZip
  • 7-Zip (plugin)

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BR technical details

Full name
Brotli compressed file
Extensions
.br
MIME type
application/x-brotli
Compression
Lossless
Developer
Google
Specification
datatracker.ietf.org

BR questions, answered

How do I open a .br file?

The brotli CLI, 7-Zip and many archive tools decompress it; browsers use it invisibly as content-encoding. dexrr extracts .br files directly in your browser.

Can I convert BR files online?

Yes, dexrr decompresses .br and can repack the contents locally in your browser to gzip, zip or plain files.

Is Brotli better than gzip?

On web text, clearly. It is ~20–26% smaller at equivalent quality levels. Gzip remains faster to encode and readable absolutely everywhere.

Why does my downloaded .br file look like a web page?

It is one, a Brotli-compressed asset saved with its encoding extension. Decompress it to get the real HTML/CSS/JS inside.

Is the BR format outdated?

No, it is the current standard for HTTP text compression and the engine inside WOFF2 web fonts.