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Fortio vs Grafana k6: catalog facts
Fortio	Grafana k6
Free Free to use, with the source code published on GitHub.	Free The k6 tool itself is free and open source.
Web, Self-hosted, Command line	Command line
Fixed queries-per-second load for repeatable tests Latency histograms and detailed statistics	Test scenarios written in plain JavaScript Single command-line tool, also usable in Docker
Aimed at developers and operators rather than casual users Measures servers under load, not page rendering speed	Requires writing scripts; no graphical test builder in the tool itself Aimed at developers rather than casual site owners
Downloadable app, Self-hosted	Downloadable app
Closed source	Open source
License not stated	License not stated
No account needed	No account needed
Works offline	Works offline
Official website Full listing and sources Checked October 2, 2026	Official website Full listing and sources Checked September 23, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.