Arize Phoenix alternatives
9 other agent observability & evals compared on one normalised price. The comparable column is the cheapest paid plan with a fixed monthly fee (per seat where noted). Usage overages (traces, units, GB) differ a lot between vendors; they are in the plan column.
| Vendor | Plan | Listed price (as on vendor page) | $/mo | Free tier | Source | Status | Checked |
|---|---|---|---|---|---|---|---|
| Opik (Comet) | Pro Cloud | $19 per month (per user); extra spans $5/100k | $19/mo | Free cloud plan $0; open source self-host | source | verified | 2026-10-19 |
| Langfuse | Core | $29/month incl. 100k units, then $8/100k units Pro $199, Enterprise $2499. | $29/mo | Hobby: free | source | verified | 2026-10-19 |
| Laminar | Starter | $30/month incl. 3 GB data, then $2/GB Pro $150/month. | $30/mo | Free: $0/month, 1 GB data | source | verified | 2026-10-19 |
| LangSmith | Plus | $39 per seat per month, then pay as you go Traces billed in LSU units ($1.00 / LSU). | $39/mo | Developer: $0/seat, 1 seat | source | verified | 2026-10-19 |
| AgentOps | Pro | From $40/month, pay as you go | $40/mo | Basic: $0, free up to 5,000 events | source | verified | 2026-10-19 |
| Logfire | Team | $49/month incl. 10M records, then $2 per million Growth $249/month. | $49/mo | Personal: free, 10M records/month hard-capped at $0 | source | verified | 2026-10-19 |
| Arize Phoenix | AX Pro | $50/month Open-source Phoenix is self-hostable. | $50/mo | AX Free: $0 | source | verified | 2026-10-19 |
| Weights & Biases Weave | Pro | Starts at $60/month, billed monthly | $60/mo | Free: $0/mo | source | verified | 2026-10-19 |
| Helicone | Pro | $79 per month + usage; Team $799 | $79/mo | Hobby: free, 10,000 free requests | source | verified | 2026-10-19 |
| Braintrust | Pro | $249/month incl. $100 credits, 5 GB data | $249/mo | Starter: $0/month, $10 credits, 1 GB data | source | verified | 2026-10-19 |