Our take
Pick Axiom if app / platform teams who will stay on Personal $0 (500 GB load, 10 GB-hours query, 25 GB store, 30-day retention, no card) while they ingest a first dataset, then buy Cloud at $25/month when they want the Always Free 1 TB / 100 GB-hours / 100 GB envelope and configurable retention. Pick Opik if agent teams who will stay on OSS $0 or Free Cloud $0 (25k spans, 10 members), then buy Pro Cloud at $19/month
agent trace + eval desk
Best for
Axiom Logs you start on Personal at $0 (no card) or Cloud at $25 + usage
Opik Spans you can self-host at $0 or rent from $0 Cloud / $19 Pro
Free plan
Axiom $0 · /month, permanent, no card. 500 GB/mo data-loading compute. 10 GB-hours/mo query compute. 25 GB storage. 30-day retention
Opik $0 · self-host. Full observability + agent testing. Same codebase as hosted. Agent Playground included
Lowest paid
Axiom Storage $0.03
Opik Not published by the vendor
Next step up
Axiom Data loading (ingest) $0.12
Opik
Coding agent
Axiom
Opik Experiments + datasets
Runs where
Axiom Local; you host it
Opik Local; you host it
Watch out
Axiom Personal is 25 GB stored and 30-day retention
Opik Free Cloud is 25k spans
Last checked
Axiom 2026-10-22 · axiom.co/pricing
Opik 2026-10-22 · comet.com/site/pricing
app / platform teams who will stay on Personal $0 (500 GB load, 10 GB-hours query, 25 GB store, 30-day retention, no card) while they ingest a first dataset, then buy Cloud at $25/month when they want the Always Free 1 TB / 100 GB-hours / 100 GB envelope and configurable retention.
Read the Axiom pageagent teams who will stay on OSS $0 or Free Cloud $0 (25k spans, 10 members), then buy Pro Cloud at $19/month when they need 100k spans and 50 seats.
Read the Opik page