Microsoft introduces Brotli compression to Edge

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Microsoft’s Senior Program Manager of the Microsoft Edge Team, Rob Trace, announced Brotli as the newest “HTTP content-encoding method” available in Microsoft Edge. Current Windows Insider Program members running Windows 10 Insider preview build 14986 (and beyond) can take advantage of Brotli support in Edge now. Stable builds of the Windows 10 Creators Update will be receiving Brotli support in Edge sometime in early 2017.

According to Trace, Brotli will be “broadly interoperable” in other browsers as well, including Firefox, and Chrome.

“Brotli is a compression format defined in RFC 7932, previously available as part of the WOFF2 font format. When used as an HTTP content-encoding method, Brotli achieves up to 20% better compression ratios with similar compression and decompression speeds (PDF). This ultimately results in substantially reduced page weight for users, improving load times without substantially impacting client-side CPU costs. As compared to existing algorithms, like Deflate, Brotli compression is more efficient in terms of file size and CPU time.

In the current preview release, Microsoft Edge supports Brotli on HTTPS and HTTP connections. In a future preview release, we will update this behavior to only advertise Brotli support on HTTPS connections. Like Chrome, we will continue to decode Brotli content on HTTP connections. Note that in the current preview release, there is a known issue which results in the F12 Developer Tools incorrectly not showing the accept encoding response header. This is tracked as issue 9771399 on”

If you have any feedback, questions, or issues, reach out to the Microsoft Edge team on Twitter.