
Phoenix
Claim this toolEvaluate, experiment, and optimize AI products in real time with open-source LLM tracing.
Visit WebsiteThe Bottom Line
Entry price
Free plan available, paid tiers above
Biggest pro
Open-source and self-hostable, offering flexibility and no vendor lock-in.
Biggest con
Advanced features like dedicated support and custom data limits are only available in higher-tier paid plans.
TL;DR - Phoenix
- Open-source LLM tracing and evaluation platform.
- Provides real-time visibility, debugging, and optimization for AI products.
- Features interactive prompt playgrounds, evaluation libraries, and dataset visualization.
What is Phoenix?
Available on: Web
Pros & Cons
Pros
- Open-source and self-hostable, offering flexibility and no vendor lock-in.
- Provides deep observability into LLM behavior and decision-making.
- Facilitates rapid experimentation and iteration with interactive playgrounds.
- Supports both automated and human feedback for comprehensive evaluations.
- Strong community support and integrations with popular LLM frameworks.
Cons
- Advanced features like dedicated support and custom data limits are only available in higher-tier paid plans.
- The free SaaS tier has limited trace spans and ingestion volume.
- Requires some technical expertise for self-hosting and full utilization.
Preview
Key Features
Pricing Plans
Pricing checked Jul 12, 2026
Phoenix Small teams and smaller data
Free & open source
- Trace spans user managed
- Ingestion volume user managed
- Projects user managed
- Retention user managed
- Support add-on dedicated support
AX Free
Free
- 25k trace spans per month
- 1 GB ingestion volume per month
- 7 days retention
- Alyx (Arize agent)
- Online evals
- Product observability (monitors & custom metrics)
- Community support
AX Pro
$50 / month
- 50k trace spans per month
- 10 GB ingestion volume per month
- 15 days retention
- Everything in AX Free
- Higher rate limits
- Longer retention
- Email support
AX Enterprise
Custom
- Custom trace spans
- Custom ingestion volume
- Custom projects
- Configurable retention
- Everything in AX Pro
- Dedicated support
- Uptime SLA
- Custom data limits
Is Phoenix worth the price?
Phoenix offers a very generous free tier with its open-source solution and a substantial free tier for AX, making it highly accessible.
The AX Pro tier at $50/month provides good value for growing teams needing more capacity. This pricing structure is best for individual developers and small to medium-sized teams focused on AI product evaluation and optimization.
Hidden Costs & Gotchas
Overage fees for exceeding trace spans/ingestion
Add-ons for dedicated support
Self-hosting is an add-on
Enterprise features are custom priced
How Phoenix Compares to Competitors
Compared to similar LLM observability platforms like LangChain Hub (which has a free tier but scales quickly), Phoenix's AX Pro at $50/month offers a competitive amount of trace spans and ingestion volume. While some platforms might offer more features in their free tiers, Phoenix's open-source option provides unparalleled flexibility and cost control for those willing to self-manage.
How Phoenix's pricing compares
At $50/mo, Phoenix is mid-range of its 3 direct competitors ($19 to $100/mo across the set).
Entry paid plan, monthly. Pricing checked Jul 12, 2026.
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Phoenix FAQ
How does Phoenix help in optimizing AI products?
Which teams benefit most from using Phoenix?
How does Phoenix compare to LangSmith?
What kind of limitations should users be aware of with Phoenix?
How is Phoenix priced?
Can Phoenix integrate with existing LLM development workflows?
How does Phoenix assist in debugging LLM applications?
Source: phoenix.arize.com