Best AI Agent Observability Tools in 2026
30 ai agent observability tools ranked on what their makers publish — plans and prices, free tiers, platforms and the facts on their own pages.
30ranked
25free plans on this page
$19/molowest paid tier
3 Oct 2026last checked
| # | App | Score | From | Free plan | Paid from | Trace retention | Session replay | Prompt and tool tracing | Deployment options | |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Opik | 8.1 | $19/mo | Yes | 19 /mo | — | — | — | — | View |
| 2 | Langfuse | 7.9 | $29/mo | Yes | 29 /mo | — | — | — | — | View |
| 3 | W&B Weave | 7.8 | $60/mo | Yes | 60 /mo | — | — | — | — | View |
| 4 | LangWatch | 7.6 | Free | Yes | — | — | — | — | — | View |
| 5 |  Arize AX | 7.6 | $50/mo | Yes | 50 /mo | — | — | — | — | View |
| 6 |  OpenLIT | 7.6 | Free | Yes | — | — | — | — | self_hosted | View |
| 7 |  Arize Phoenix | 7.5 | Free | Yes | — | — | — | — | — | View |
| 8 | HoneyHive | 7.4 | Free | Yes | — | — | — | — | — | View |
| 9 | LangSmith | 7.4 | Free | Yes | — | — | — | — | — | View |
| 10 |  Traceloop | 7.3 | Free | Yes | — | — | Yes | Yes | — | View |
| 11 | Helicone | 7.3 | $79/mo | Yes | 79 /mo | — | — | — | — | View |
| 12 | Laminar | 7.1 | $30/mo | Yes | 30 /mo | — | — | — | — | View |
| 13 |  MLflow Tracing | 7.0 | Free | Yes | — | — | Yes | Yes | hybrid | View |
| 14 |  Respan (formerly Keywords AI) | 6.9 | Free | Yes | 199 /mo | — | — | — | — | View |
| 15 |  TraceRoot | 6.9 | $30/mo | Yes | — | 30 days | Yes | Yes | — | View |
| 16 | AgentOps | 6.8 | Free | Yes | 40 /mo | — | — | — | — | View |
| 17 |  Traccia | 6.8 | $99/mo | Yes | 99 /mo | 30 days | Yes | Yes | hybrid | View |
| 18 |  VoltOps | 6.8 | $50/mo | Yes | 50 /mo | 90 days | Yes | Yes | — | View |
| 19 | Fiddler AI | 6.7 | Free | Yes | — | — | — | — | — | View |
| 20 | Maxim AI | 6.7 | $29/mo | Yes | — | — | — | — | — | View |
| 21 | Galileo | 6.6 | $100/mo | Yes | 100 /mo | — | — | — | — | View |
| 22 |  LogicGaze | 6.5 | Free | Yes | — | — | Yes | Yes | — | View |
| 23 | Agenta | 6.5 | $29/mo | Yes | 29 /mo | — | — | — | — | View |
| 24 | SigNoz | 6.4 | $19/mo | Yes | 49 /mo | — | — | — | — | View |
| 25 |  Hexel | 6.1 | Free | Yes | — | 30 days | Yes | — | cloud | View |
Is your app on this list?
Numbered spots on this list can be sponsored. They are labelled, and the editorial order and scores never change for payment.
Questions about this list
Which ai agent observability tool is ranked first on Freedom251?
Opik is ranked #1 of 30 with a score of 8.1. Langfuse is second and W&B Weave third.
How many of these have a free plan?
25 of the 25 on this page publish a free plan on their own pricing pages.
Which is the cheapest paid option?
On this page, Opik has the lowest first paid tier we found: $19/mo.
How is this list ranked?
Ranked free-and-open first: a usable free tier and open-source code, then the platforms it runs on and its documentation. Paid placements never change a rank.