Best AI Agent Observability Tools in 2026
Updated
In short: SigNoz is ranked #1 of 32 as of 4 October 2026, ahead of Agenta and PetalTrace. The best-ranked option with a free plan is Agenta. The lowest first paid tier on this page is Amazon Bedrock Data Automation at $0.01/mo.
When you need visibility into AI agent behavior, compare what each tool exposes across a run: framework support, prompt and tool traces, session replay, and trace retention. Cost tracking adds a way to consider usage, while deployment options, free-plan availability, and paid-from pricing help frame access. The ranking opens with Opik and Langfuse, followed by Arize AX and W&B Weave; SigNoz, OpenLIT, LangWatch, and Traceloop also appear among the first entries. Weigh the tracing and replay capabilities you need against how you plan to deploy and what cost information you want to review.
32 AI agent observability tools ranked on what their makers publish — plans and prices, free tiers, platforms and the facts on their own pages.
Recognised 40% · Phone app 26% · Documented 20% · Free plan 14% of the score
- 1 SigNoz iPhone + Android RecognisedPhone appDocumentedFree plan 7.8$19/mo
- 2 Agenta No phone app RecognisedPhone appDocumentedFree plan 6.4$29/mo
- 3 PetalTrace No phone app RecognisedPhone appDocumentedFree plan 6.4Free Session replay: YesPrompt and tool tracing: Yes
- 4 Traccia No phone app RecognisedPhone appDocumentedFree plan 6.4$99/mo Trace retention: 30 daysSession replay: YesPrompt and tool tracing: Yes
- 5 TraceRoot No phone app RecognisedPhone appDocumentedFree plan 6.4$30/mo Trace retention: 30 daysSession replay: YesPrompt and tool tracing: Yes
- 6 VoltOps No phone app RecognisedPhone appDocumentedFree plan 6.4$50/mo Trace retention: 90 daysSession replay: YesPrompt and tool tracing: Yes
- 7 Arize AX No phone app RecognisedPhone appDocumentedFree plan 6.3$50/mo
- 8 Braintrust No phone app RecognisedPhone appDocumentedFree plan 6.3$249/mo
- 9 Galileo No phone app RecognisedPhone appDocumentedFree plan 6.3$100/mo
- 10 Helicone No phone app RecognisedPhone appDocumentedFree plan 6.3$79/mo
- 11 Laminar No phone app RecognisedPhone appDocumentedFree plan 6.3$30/mo
- 12 Langfuse No phone app RecognisedPhone appDocumentedFree plan 6.3$29/mo
- 13 LogicGaze No phone app RecognisedPhone appDocumentedFree plan 6.3Free Session replay: YesPrompt and tool tracing: Yes
- 14 Maxim AI No phone app RecognisedPhone appDocumentedFree plan 6.3$29/mo
- 15 MLflow Tracing No phone app RecognisedPhone appDocumentedFree plan 6.3Free Session replay: YesPrompt and tool tracing: Yes
- 16 OpenLIT No phone app RecognisedPhone appDocumentedFree plan 6.3Free
- 17 Opik No phone app RecognisedPhone appDocumentedFree plan 6.3$19/mo
- 18 Respan (formerly Keywords AI) No phone app RecognisedPhone appDocumentedFree plan 6.3$16.58/mo
- 19 Traceloop No phone app RecognisedPhone appDocumentedFree plan 6.3Free Session replay: YesPrompt and tool tracing: Yes
- 20 W&B Weave No phone app RecognisedPhone appDocumentedFree plan 6.3$60/mo
- 21 Amazon Bedrock Data AutomationAmazon Web Services No phone app RecognisedPhone appDocumentedFree plan 5.7$0.01/mo
- 22 Observe No phone app RecognisedPhone appDocumentedFree plan 5.5
- 23 Hexel No phone app RecognisedPhone appDocumentedFree plan 5.4 Trace retention: 30 daysSession replay: Yes
- 24 AgentOps No phone app RecognisedPhone appDocumentedFree plan 5.2
- 25 Amazon Nova ReelAmazon Web Services No phone app RecognisedPhone appDocumentedFree plan 5.2
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 Samsung Mobile US Press?
SigNoz is ranked #1 of 32 with a score of 7.8. Agenta is second and PetalTrace third.
How many of these have a free plan?
20 of the 25 on this page publish a free plan on their own pricing pages.
Which is the cheapest paid option?
On this page, Amazon Bedrock Data Automation has the lowest first paid tier we found: $0.01/mo.
How is this list ranked?
Ranked mobile-first: a phone app alongside the web or desktop product, a free tier and the depth of its documentation. Paid placements never change a rank.