Best AI Agent Observability Tools in 2026
Updated
In short: PetalTrace is ranked #1 of 32 as of 4 October 2026, ahead of OpenLIT and W&B Weave. The best-ranked option with a free plan is OpenLIT. The lowest first paid tier on this page is Amazon Bedrock Data Automation at $0.01/mo.
To understand what AI agents do across their sessions, observability tools provide different ways to follow activity, prompts, tool use, and costs. Compare agent framework support with prompt and tool tracing, session replay, cost tracking, and trace retention. Deployment options, free-plan availability, and paid starting points add practical factors to consider. Opik, Langfuse, and W&B Weave are among the first entries, followed by OpenLIT and Arize AX. Think about what you need to inspect during agent runs and how long traces should remain available, then compare those needs with each tool’s listed features and deployment choices.
32 AI agent observability tools ranked on what their makers publish — plans and prices, free tiers, platforms and the facts on their own pages.
#1 PetalTrace Top pick · 7.4 Free plan · Free
#2 OpenLIT Runner-up · 7.2 Free plan · Free
#3 W&B Weave Also great · 7.2 Free plan · $60/mo
- Free plan apiLinuxmacOSself-hostedWebWindows
- Session replay
- Yes
- Prompt and tool tracing
- Yes
- Deployment options
- self_hosted
RecognisedDocumentedFree planPlatforms - Free plan apiLinuxmacOSself-hostedWebWindows
- Free plan
- Yes
- Deployment options
- self_hosted
RecognisedDocumentedFree planPlatforms - Free planFree trial apiLinuxmacOSself-hostedWebWindows
- Free plan
- Yes
- Paid from
- 60 /mo
RecognisedDocumentedFree planPlatforms$60/mofirst paid tier About W&B WeaveVisit site - Free planFree trial AndroidapiiOSself-hostedWeb
- Free plan
- Yes
- Paid from
- 49 /mo
RecognisedDocumentedFree planPlatforms$19/mofirst paid tier About SigNozVisit site - Free planFree trial apiLinuxself-hostedWeb
- Free plan
- Yes
- Paid from
- 19 /mo
RecognisedDocumentedFree planPlatforms$19/mofirst paid tier About OpikVisit site - Free plan apiself-hostedWeb
- Free plan
- Yes
- Paid from
- 29 /mo
RecognisedDocumentedFree planPlatforms$29/mofirst paid tier About AgentaVisit site - Free plan apiself-hostedWeb
- Free plan
- Yes
- Paid from
- 29 /mo
RecognisedDocumentedFree planPlatforms$29/mofirst paid tier About LangfuseVisit site - Free planFree trial apiWeb
- Free plan
- Yes
- Paid from
- 99 /mo
- Trace retention
- 30 days
- Session replay
- Yes
- Prompt and tool tracing
- Yes
- Deployment options
- hybrid
RecognisedDocumentedFree planPlatforms$99/mofirst paid tier About TracciaVisit site - Free plan Web
- Free plan
- Yes
- Trace retention
- 30 days
- Session replay
- Yes
- Prompt and tool tracing
- Yes
RecognisedDocumentedFree planPlatforms$30/mofirst paid tier About TraceRootVisit site - Free planFree trial apiself-hostedWeb
- Free plan
- Yes
- Paid from
- 50 /mo
- Trace retention
- 90 days
- Session replay
- Yes
- Prompt and tool tracing
- Yes
RecognisedDocumentedFree planPlatforms$50/mofirst paid tier About VoltOpsVisit site - Free plan apiself-hostedWeb
- Free plan
- Yes
- Paid from
- 50 /mo
RecognisedDocumentedFree planPlatforms$50/mofirst paid tier About Arize AXVisit site - Free plan apiself-hostedWeb
- Free plan
- Yes
- Paid from
- 249 /mo
RecognisedDocumentedFree planPlatforms$249/mofirst paid tier About BraintrustVisit site - Free plan apiself-hostedWeb
- Free plan
- Yes
- Paid from
- 100 /mo
RecognisedDocumentedFree planPlatforms$100/mofirst paid tier About GalileoVisit site - Free planFree trial apiself-hostedWeb
- Free plan
- Yes
- Paid from
- 79 /mo
RecognisedDocumentedFree planPlatforms$79/mofirst paid tier About HeliconeVisit site - Free plan apiself-hostedWeb
- Free plan
- Yes
- Paid from
- 30 /mo
RecognisedDocumentedFree planPlatforms$30/mofirst paid tier About LaminarVisit site - Free plan apiself-hostedWeb
- Free plan
- Yes
- Session replay
- Yes
- Prompt and tool tracing
- Yes
RecognisedDocumentedFree planPlatforms - Free planFree trial apiself-hostedWeb
- Free plan
- Yes
RecognisedDocumentedFree planPlatforms$29/mofirst paid tier About Maxim AIVisit site - Free plan apiself-hostedWeb
- Free plan
- Yes
- Session replay
- Yes
- Prompt and tool tracing
- Yes
- Deployment options
- hybrid
RecognisedDocumentedFree planPlatforms - Free planFree trial apiself-hostedWeb
- Free plan
- Yes
- Paid from
- 199 /mo
RecognisedDocumentedFree planPlatforms$16.58/mofirst paid tier About Respan (formerly Keywords AI)Visit site - Free plan apiself-hostedWeb
- Free plan
- Yes
- Session replay
- Yes
- Prompt and tool tracing
- Yes
RecognisedDocumentedFree planPlatforms - Free trial apiLinuxmacOSWebWindows
- Free plan
- No
RecognisedDocumentedFree planPlatforms - apiRecognisedDocumentedFree planPlatforms$0.01/mofirst paid tier About Amazon Bedrock Data AutomationVisit site
- Web
- Free plan
- Yes
- Paid from
- 40 /mo
RecognisedDocumentedFree planPlatforms - Web
- Free plan
- Yes
RecognisedDocumentedFree planPlatforms -
- Free plan
- Yes
- Trace retention
- 30 days
- Session replay
- Yes
- Deployment options
- cloud
RecognisedDocumentedFree planPlatforms
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 Everything Xiaomi?
PetalTrace is ranked #1 of 32 with a score of 7.4. OpenLIT is second and W&B Weave 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 on what each maker publishes: documentation depth, a free tier and the platforms it runs on. Paid placements never change a rank.