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Head-to-head · LLM Observability Tools

Arize Phoenix vs Opik

  • Updated Oct 2026
  • Both researched from official sources
  • 7 checks side by side
Higher score Arize Phoenix #3 in LLM Observability Tools 9.2/10 Free plan Free plan✓ 6 of 6 features Visit Arize Phoenix
Opik #4 in LLM Observability Tools 9.1/10 Free plan Free plan✓ 6 of 6 features Visit Opik

Arize Phoenix leads on 0 checks, Opik on 0, and 7 are even. Who comes out ahead on the 7 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreArize Phoenix · 9.2/10
  • Free planboth

Arize Phoenix scores higher on our rubric for llm observability tools: 9.2 against 9.1 out of 10; our editors rank them #3 and #4.

Arize Phoenix is the better fit for developers wanting free open-source LLM observability. Opik is the better fit for cost-conscious teams needing full-stack observability.

  • Arize Phoenix fits best

    Developers wanting free open-source LLM observability

  • Opik fits best

    Cost-conscious teams needing full-stack observability

Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.

Side by side

Feature Arize Phoenix 9.2/10 Visit ↗ Opik 9.1/10 Visit ↗
At a glance
Editor score 9.2 9.1
Ranking #3 in LLM Observability Tools #4 in LLM Observability Tools
Best for Developers wanting free open-source LLM observability Cost-conscious teams needing full-stack observability
Pricing model Free Free plan + paid
Starting price Free $19/mo
Free plan ✓ ✓
Free trial — —
Deployment Cloud, Self-hosted Cloud, Self-hosted
Platforms Web Web
Support Community, Docs Email, Community, Docs
Integrations 11 integrations 40+ integrations
Built for Solo, Small business, Mid-market, Enterprise Solo, Small business, Mid-market, Enterprise
Features Arize Phoenix 6/6 · Opik 6/6
LLM tracing ✓ ✓
LLM evaluations ✓ ✓
Prompt management ✓ ✓
Agent tracing ✓ ✓
Retrieval tracing ✓ ✓
Token cost tracking ✓ ✓
Specs
Deployment options Both Both
Our review
Pros
  • Free open-source plan with tracing, evaluations, and prompt iteration
  • Tracks retrieval, tool use, prompts, experiments, and token-based costs
  • Supports web, API, self-hosted deployment and multiple AI frameworks
  • Free self-hosted and cloud options cover core observability needs
  • Traces model calls, tools, retrieval steps, and agent actions
  • Tracks evaluations, prompts, human feedback, tokens, and model costs
Cons
  • Focused on AI applications and agents rather than general observability
  • Instrumentation coverage centers on Python, TypeScript, and Java
  • Hosted Phoenix Cloud is distinct from local-first and self-hosted use
  • Enterprise pricing is custom rather than published
  • Self-hosted deployment requires your own infrastructure
  • Its broad scope may exceed teams needing only basic tracing
Our verdict

Arize Phoenix is an open-source observability and evaluation platform for AI applications and agents. It is designed for developers who need visibility into model calls, retrieval, tool use, and custom application logic. The platform…

Read the review →

Opik is an open-source LLM observability and evaluation platform from Comet for teams building chatbots, retrieval-augmented generation pipelines, and multi-step agents. It records model calls, tool invocations, retrieval steps, and agent…

Read the review →
  1. Arize PhoenixLLM Observability Tools 9.2Free plan
  2. OpikLLM Observability Tools 9.1Free plan

Strengths and trade-offs

  • Arize Phoenix — where it wins

    • Free open-source plan with tracing, evaluations, and prompt iteration
    • Tracks retrieval, tool use, prompts, experiments, and token-based costs
    • Supports web, API, self-hosted deployment and multiple AI frameworks

    Where it doesn't

    • Focused on AI applications and agents rather than general observability
    • Instrumentation coverage centers on Python, TypeScript, and Java
    • Hosted Phoenix Cloud is distinct from local-first and self-hosted use

  • Opik — where it wins

    • Free self-hosted and cloud options cover core observability needs
    • Traces model calls, tools, retrieval steps, and agent actions
    • Tracks evaluations, prompts, human feedback, tokens, and model costs

    Where it doesn't

    • Enterprise pricing is custom rather than published
    • Self-hosted deployment requires your own infrastructure
    • Its broad scope may exceed teams needing only basic tracing

More comparisons

All LLM observability tools comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update