k6 vs Vegeta

k6 has no write-up on Specifiction yet; its figures are above.

Vegeta is a free, open-source HTTP load-testing tool and Go library that sends requests at a constant rate. Its command-line interface is built for UNIX-style composition, while the library offers use from Go programs. The project states that its load measurements avoid coordinated omission and that distributed testing is supported. Reports can be written as text, JSON, histograms, or HDR plots, and results can also be encoded as CSV, Gob, or JSON. The attack command can expose an optional Prometheus exporter. HTTP/2 works when supported by the server, including HTTP/2 over TCP without TLS. TLS options include client certificates and keys, custom root certificates, and ignoring invalid server certificates. The documented request timeout defaults to 30 seconds, with zero disabling timeouts. Prebuilt binaries, package-manager installs, distribution packages, and source builds are documented for Linux, macOS, Windows, API use, and self-hosting. The repository uses the MIT license.