Vegeta vs Apache JMeter

Free and open source

Free and open source

Free and open source. You pay in engineering time and CI minutes.

Free. Costs are load-generator infrastructure and, commonly, a cloud execution service such as BlazeMeter.

Everything, self-hosted

Everything, self-hosted

Established

OSS community · since 2013

Category standard

Apache Software Foundation · since 1998

• Constant-rate model avoids the coordinated-omission problem that distorts VU-based tools.
• Single static binary, trivial to run anywhere.
• Composable output for scripting and pipelines.

• Protocol coverage no modern tool matches — JDBC, JMS, LDAP, mainframe-adjacent protocols.
• GUI test-plan building is accessible to testers who do not code.
• Enormous body of documentation, plugins and available expertise.

• No scenarios or session state — one target list, one rate.
• No GUI or built-in reporting beyond plots.
• Go library usage required for anything sophisticated.

• Thread-per-user model is memory-hungry; high load needs a cluster where k6 needs one box.
• JMX test plans are XML that merges terribly in version control.
• The GUI must not be used for actual load generation, which trips up nearly every beginner.

Backend engineers who want rigorous constant-rate measurements of an endpoint.

Enterprise performance teams needing protocol breadth and a GUI-based workflow.