Zach’s ugly mug (his face) Zach Leat­herman

Bridgy for Webmentions with Brotli

June 29, 2019

Summary: Just a fair warning if you use the amazing Bridgy service to gather webmentions from social networking sites. It won’t actually work with your site if you’re using Brotli compression. Use gzip for your HTML requests instead of Brotli and it will work fine.

On June 11, 2019 I tweeted:

Unfortunately, I would learn much later that this would cause my webmentions to stop working too!

I logged into webmention.io and had zero new webmentions from Twitter coming in. My webmentions from Twitter come from Bridgy. I logged into my Bridgy admin panel and saw a bunch of errors:

No webmention support: https://www.zachleat.com/web/css-tricks-web-fonts/

Apparently this stopped working when I added Brotli compression to my web site. Bridgy doesn’t support Brotli compression so when it fetches my site it can’t decompress my HTML content for parsing. My site does correctly fallback to uncompressed output when Brotli support is not advertised in the request’s Accept-Encoding header, but unfortunately Google App Engine assumes that all applications support Brotli compression and always includes this in request headers made on the service 😱. Star this issue to ask Google App Engine developers to fix this!

Anyway, I modified my site to compress gzip on HTML requests and use Brotli for everything else (if supported). I’ll go back to full Brotli after this issue is fixed 🏆.

Hope this helps someone else!

Zach Leatherman is a builder for the web at Font Awesome and the creator of Build Awesome (née Eleventy/11ty), an award-winning open source website generator. He measures website performance with speedlify and at one point became too fixated on web fonts. He has given 86 talks in nine different countries at events like Beyond Tellerrand, Smashing Conference, Jamstack Conf, CSSConf, and The White House. Learn more about Zach »