Guide / Choosing a tool
Best LLM observability tools.
The best tool is the one that matches how you collect traces, what you need to see and where your data has to live. Here is how to choose, and who each option fits.
How to choose
Five questions that decide it.
01
How traces get in
Look for OpenTelemetry support so your instrumentation is not locked to one vendor.
02
Whole runs, not single calls
An agent makes many model and tool calls per task. You want them in one trace, in order.
03
Cost you can act on
Cost per run and per task matters more than the monthly total.
04
Evaluation and alerts
Tracing tells you what happened. Evaluation and alerts tell you what to fix first.
05
Where data lives
Check hosting options, such as an EU region or self-hosting, before you commit.
The options
Who each one fits.
We make Tracify, so read this with that in mind. Descriptions of other tools are short summaries; check their sites for current features and pricing.
| Tool | Best when you | Details |
|---|---|---|
| Tracify | Run agents and want managed tracing, cost, alerts and evaluation, with an EU region. | Trace viewer |
| Langfuse | You want to read, modify or self-host the source. | Tracify vs Langfuse |
| LangSmith | Your stack is mostly LangChain or LangGraph. | Tracify vs LangSmith |
| Helicone | You want a gateway in front of providers for routing and fallbacks. | Tracify vs Helicone |
| Arize Phoenix | You want a free tool you run yourself, with the source available. | Tracify vs Arize Phoenix |
| Braintrust | Evaluation and experiment workflows are your top priority. | Tracify vs Braintrust |
| Datadog LLM Observability | Your whole company already runs on Datadog and wants one pane of glass. | Tracify vs Datadog LLM Observability |
Questions
Quick answers.
- What is LLM observability?
- LLM observability is recording the model calls, tool calls, cost, latency and errors of an AI application so its behavior can be inspected and debugged in production.
- What is the difference between LLM observability and AI agent observability?
- Agent observability follows whole multi-step runs, including tool calls, retries and handoffs, instead of single model requests.
- Do I need a dedicated tool or can I use general APM?
- General monitoring tools can show that a request was slow. A dedicated tool also shows prompts, tool calls, token cost and quality scores for each step.
- Can I switch tools later?
- It is easier if you send traces over OpenTelemetry, because the instrumentation stays the same when the backend changes.
- Is Tracify the best choice?
- It depends on your needs. Tracify fits teams that want managed tracing, cost, alerts and evaluation for agents, with an EU region. Other tools fit other needs, and each comparison page says when.
Next: what is LLM observability, send OpenTelemetry traces, pricing.