This page is served by the thing it describes.
k3 turns a folder of static files into a bootable x86-64 HTTPS server. The whole system (boot code, network driver, TCP, TLS 1.3, HTTP) is about 13 KB of assembly, and the files come behind it in the same image. There is no operating system underneath: no kernel, no shell, no file system, nothing to log into.
What answered your request is a cloud server with two shared virtual processors and 4 GB of memory, running nothing but that image.
| on that server | k3 | nginx + OpenSSL |
|---|---|---|
| new TLS 1.3 connections a second | 7,500 to 9,000 | 2,100 to 2,200 |
| small pages a second, connections kept | 105,000 to 114,000 | 30,000 to 31,000 |
| a 1.5 MiB file | 165 MB/s | 750 MB/s |
| memory for a TLS connection that is held | 128 bytes | 25.8 KiB |
It is fast at what a site is mostly made of and slow at large files, it speaks TLS 1.3 only, it serves GET and HEAD and nothing else, and a change of content or certificate is a new image and a reboot. That is the design: clunky, limited, small, and hard to break into.
How the numbers were measured, and what they do not say, is in the project's
bench/README.md.