Arize Phoenix vs Langfuse
Compare Arize Phoenix and Langfuse for tracing, prompt management and evaluation, with Lunary for conversation review and user feedback.
$20 per user / month. Payment required to activate your workspace.
Phoenix and Langfuse both support open-source AI observability. Try Lunary when the decision hinges on reviewing customer conversations with your team.
Lunary
Our pick for messages, feedback and linked agent runs.
Arize Phoenix
Consider for OpenInference tracing and span replay.
Langfuse
Consider for tracing and prompt deployment workflows.
At a glance
| Workflow | Lunary | Arize Phoenix | Langfuse |
|---|---|---|---|
| Investigation context | Messages linked to agent and LLM runs | Sessions and OpenInference traces | Application traces with quality scores |
| Prompt editing | Templates and collaborative drafts | Versions, playground and span replay | Central prompt management and versions |
| Prompt rollout | Fetch templates through SDKs | Store and deploy prompts through SDKs | SDK retrieval with deployment labels |
| Pilot question | Can our team explain this poor reply? | Can we replay and diagnose this span? | Can we trace this prompt version in use? |
See your workflow in Lunary.
Explore conversations, traces and prompt versions with our team.
Inspect the same failed request
Phoenix builds on OpenTelemetry and OpenInference. Langfuse records model calls, retrieval and tools as application traces. Lunary links those execution details to chat messages so the user interaction stays part of the investigation.
Test how a revision reaches production
Phoenix combines prompt versions, a playground and span replay. Langfuse uses central prompts, versioning and deployment labels. Lunary offers templates and shared drafts with a playground for models or your own endpoint.
Include the people reviewing quality
Bring a real multi-turn case and the reviewers who handle customer issues. Try Lunary’s chat replay and feedback workflow alongside both tools. Keep the same expected behavior and test examples when comparing the resulting prompt changes.
Questions & answers
Does Phoenix have prompt management?
Yes. It includes prompt versions, a playground, SDK access and span replay.
Is Langfuse only a tracing tool?
No. Its platform also includes evaluations and prompt management.
When should I choose Lunary?
We recommend Lunary when your team needs chat replay, message feedback and linked traces to understand customer issues before revising prompts.
By Lunary · Documentation reviewed Sep 19, 2026
Sources & methodology (10)
Based on vendor documentation, not an independent benchmark or hands-on rating. Features and plans can change.
Bring your next AI issue to Lunary.
Follow the conversation. Find the cause. Test the fix.
$20 per user / month. Payment required to activate your workspace.