| # jxl Content-Encoding explained |
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| ## What’s all this then? |
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| HTTP Content-Encoding allows transfer of resources in a compressed form. |
| Most popular Content-Encodings – `deflate` (`gzip`) and `br` – are LZ77-based general-purpose data compressors; those fit well for compression of HTML, JS and CSS. |
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| Video and image resources take 1-st and 2-nd place in the Internet traffic volume chart. Those are considered succinct. |
| However, one of the most popular image formats – JPEG – could be "repacked" to a more dense form. |
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| `jxl` Content-Encoding allows ~22% traffic reduction for JPEG images. |
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| ## Getting started |
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| First, install appropriate server plugin (e.g. `ngx_brunsli` for NGINX or `mod_brunsli` for Apache from [https://github.com/google/brunsli/tree/master/contrib](contrib)). |
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| Now server is capable to respond with compressed resources when it sees appropriate encoding in 'Accept-Encoding' header. |
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| Restriction: it is likely, that browser will send `jxl` in 'Accept-Encoding' header only over encrypted connections (HTTPS) to avoid problems with faulty proxies. |
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| ## Links |
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| Codec demo site: https://brunsli.dev/ |
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| Specification: https://arxiv.org/pdf/1908.03565.pdf |
