Helicone vs Phoenix

Helicone

Evaluation

Phoenix

Evaluation

Tagline

Helicone

Open-source LLM observability — one-line proxy install.

Phoenix

Open-source LLM and agent observability platform with tracing, evals, and experimentation built on OpenTelemetry.

Pricing

Helicone

Freemium· Free 100k req/mo; Pro from $25/mo

Phoenix

Freemium· AX Free: Free · AX Pro: $50 · AX Enterprise: Custom

Lowest paid tier

Helicone

—

Phoenix

$50 · AX Pro

captured 2026-08-08

Free trial

Helicone

Not listed

Phoenix

Yes

API

Helicone

Not listed

Phoenix

Yes

Platforms

Helicone

api

Phoenix

api

Open source

Helicone

Not listed

Phoenix

Yes

Model used

Helicone

Platform (any LLM)

Phoenix

Multi-model

Best for

Helicone

Pick Helicone when you want one-line LLM observability with no integration work.

Phoenix

Pick Phoenix if you're building LLM agents and want OpenTelemetry-native tracing and evals you can self-host without losing core features.

Not for

Helicone

Skip it when you need deep eval datasets or your workload can't tolerate a proxy hop.

Phoenix

Skip it if you want a fully managed, zero-ops observability SaaS with white-glove enterprise support out of the box.

Editorial score

Helicone

8.3 / 10

Phoenix

7.0 / 10

Use cases

Helicone

observabilitycost trackingopen source

Phoenix

llm-tracingagent-debuggingllm-evaluationprompt-experimentsrag-observability

Pros

Helicone

• One-line install
• Open source
• Generous free tier
• Cost tracking is genuinely useful

Phoenix

• Genuinely open source (ELv2) with self-host parity, not a crippled OSS shell
• Native OpenTelemetry means no vendor lock-in for instrumentation
• Covers tracing, evals, annotation, and experiments in one tool
• Framework-agnostic: LangChain, LlamaIndex, DSPy, CrewAI, raw SDK calls all work

Cons

Helicone

• Eval features less deep than Braintrust
• Proxy adds a hop

Phoenix

• Self-hosting still requires you to manage storage, retention, and upgrades
• Eval UX is less polished than some managed competitors like LangSmith
• Free cloud tier is capped at two instances

Website

Helicone

www.helicone.ai

Phoenix

phoenix.arize.com

Editorial score: rule-based, 0–10, from AI-assisted profile inputs (see /methodology) — not a user rating; “—” means unscored. “Not listed” means we have no record of it, not that it is absent. GitHub figures and prices carry the date they were checked or captured; prices are shown as published, unconverted.