kitio.aiArize AI vs Lunary
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. Lunary has the lower starting price: about $20 a month, against $50 for Arize AI.
At a glance
Best for
Category
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Arize Phoenix open source
- Agent tracing
- Online evaluations
- Drift monitoring
- Debugging copilot
- LLM request logging
- Chatbot analytics
- Prompt versioning
- Human reviews
- AI playground
- CSV and JSONL export
| Feature | Arize AI | Lunary |
|---|---|---|
| Best for | AI observability and evaluation, plus the open-source Phoenix | Observability, prompt management and evals for LLM apps |
| Category | Models & APIs | Models & APIs |
| Pricing model | Freemium | Freemium |
| Starting price | $50/mo | $20/mo |
| Free plan | Yes | Yes |
| Made by | Arize AI | Lunary |
| Based in | United States | – |
| Rating | No ratings yet | No ratings yet |
| Key features |
|
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Pricing compared
Lunary has the lower starting price: about $20 a month, against $50 for Arize AI.
Free plan
Cheapest paid plan
Top plan
Free trial
3 plans
AX Free
Free
- 25k spans/month
- 1 GB ingestion/month
- 15 days retention
- Unlimited users
AX Pro
$50/mo
- 50k spans/month
- 10 GB ingestion/month
- 30 days retention
AX Enterprise
Contact sales
- Custom plans
2 plans
Team
$20/mo
- Per user
- 50,000 events per month
- 300 playground queries per month
- Unlimited projects, 1 year history
Enterprise
Custom
- Custom limits
- Plans for larger teams
Prices in USD, checked Oct 28, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
Arize AI
- Free open-source Phoenix
- Covers classic ML and LLMs
- Strong enterprise features
- AX costs rise with volume
- Two products can confuse
- Steeper setup than simple tools
Lunary
- Prompts and traces in one tool
- Self-hosting option
- Clear per-seat pricing
- Cloud workspace requires payment up front
- Team plan caps at 10 seats
- Extra events and queries cost more
Which one should you choose?
Choose Arize AI if you want:
- Free open-source Phoenix
- Covers classic ML and LLMs
- Strong enterprise features
Watch out: ax costs rise with volume.
Choose Lunary if you want:
- Prompts and traces in one tool
- Self-hosting option
- Clear per-seat pricing
Watch out: cloud workspace requires payment up front.
Arize AI vs Lunary FAQ
What is the difference between Arize AI and Lunary?
Arize AI: AI observability and evaluation, plus the open-source Phoenix. Lunary: Observability, prompt management and evals for LLM apps. Both are models & apis tools.
Is Arize AI or Lunary cheaper?
Lunary has the lower starting price: about $20 a month, against $50 for Arize AI.
Do Arize AI and Lunary have free plans?
Arize AI: Yes. Lunary: Yes.
Who makes Arize AI?
Arize AI is made by Arize AI, based in United States.
Who makes Lunary?
Lunary is made by Lunary.
Which should I choose, Arize AI or Lunary?
Choose Arize AI if you value free open-source phoenix and covers classic ml and llms. Choose Lunary if you value prompts and traces in one tool and self-hosting option.