Arize Phoenix vs Helicone
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
AI tool · Open source
An open-source tool for tracing, evaluating and experimenting with LLM and agent applications, built on OpenTelemetry.
AI tool · Freemium
An open-source LLM observability proxy that logs requests, costs and latency with a one-line integration.
The short answer
Choose Arize Phoenix if you need…
- Local debugging of LLM traces
- OpenTelemetry-based stacks
Choose Helicone if you need…
- Quick cost and usage visibility
- Caching and rate limiting LLM calls
Side-by-side
| Arize Phoenix | Helicone | |
|---|---|---|
| Type | Prompting · Evaluation & observability | Prompting · Evaluation & observability |
| Price | Open source | Freemium |
| Platforms | Self-hosted, Web, API | Web, API, Self-hosted |
| Works with | LangChain, LlamaIndex, OpenAI | OpenAI, Anthropic |
| Hands-on tested by us | Not yet | Not yet |
| Last checked | 2026-10-29 | 2026-10-29 |
What each one is
Arize Phoenix
An open-source tool for tracing, evaluating and experimenting with LLM and agent applications, built on OpenTelemetry. Standards-based and free to run locally. Enterprise features live in Arize's paid platform.
Helicone
An open-source LLM observability proxy that logs requests, costs and latency with a one-line integration. Very easy to adopt. A proxy sits in your request path, so check reliability and data handling.
Best for
Arize Phoenix
- Local debugging of LLM traces
- OpenTelemetry-based stacks
Helicone
- Quick cost and usage visibility
- Caching and rate limiting LLM calls
Strengths
Arize Phoenix
- OpenTelemetry tracing
- LLM-as-judge evals
- Prompt playground
- Datasets and experiments
Helicone
- Proxy-based request logging
- Cost tracking
- Caching
- Prompt versioning
Frequently asked questions
What is the difference between Arize Phoenix and Helicone?
Arize Phoenix: An open-source tool for tracing, evaluating and experimenting with LLM and agent applications, built on OpenTelemetry. Helicone: An open-source LLM observability proxy that logs requests, costs and latency with a one-line integration. Arize Phoenix suits local debugging of llm traces, while Helicone suits quick cost and usage visibility.
Are Arize Phoenix and Helicone free?
Arize Phoenix: Open source. Helicone: Freemium.
What are other alternatives to Arize Phoenix and Helicone?
Other options people compare them with include Langfuse, Confident AI (DeepEval), LangSmith, Opik, promptfoo.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.