Arize Phoenix
llm-observability
Open-source LLM and agent observability built on OpenTelemetry.
Pricing
Free plan
Rating
—
Votes
0
Head-to-head comparison
Arize Phoenix vs Vellum
Compare Arize Phoenix and Vellum side by side across pricing, features, ratings, pros, cons, best-fit use cases, and alternatives.
Vellum
llm-observability
Build, evaluate, and deploy LLM apps and agents with confidence.
Pricing
Free plan
Rating
—
Votes
0
Feature comparison
Feature
Arize Phoenix
Vellum
Category
llm-observability
llm-observability
Pricing
Free plan
Free plan
Free plan
API access
Mobile app
Browser extension
Team collaboration
Custom training
Self-hosted option
Offline mode
Multi-language support
Arize Phoenix pros and cons
Free and source-available, self-hosts in one command
Built on open OpenTelemetry standards
Strong tracing and evaluation for agents and RAG
Works locally, good for private/dev-time debugging
Production-scale features require paid Arize AX
Self-hosting means you run the infrastructure
Dynatrace acquisition may change roadmap/governance
Vellum pros and cons
Combines prompt, workflow, evaluation, and deployment in one platform
Visual workflow builder lowers the barrier for cross-functional collaborators
Solid evaluation and testing tooling for pre-production quality gates
Multi-provider model support avoids lock-in
Pricing is opaque and sales-led, making budgeting hard
Not open source, and self-hosting is locked to Enterprise
Free tier is quite limited in credits, documents, and seats
Which one should you choose?
Best overall signal
Vellum
Selected using Toolglade popularity signals such as views and votes.
Best value signal
Arize Phoenix
Selected using free-plan availability and engagement signals.
Best for
Arize Phoenix
- LLM and agent tracing
- RAG debugging
- eval-driven development
- hallucination detection
- Engineers debugging LLM and agent apps
Vellum
- collaborative agent building
- prompt evaluation and testing
- deploying LLM features
- cross-functional AI teams
- Teams wanting an all-in-one build-evaluate-deploy platform
FAQ
Is Arize Phoenix better than Vellum?
It depends on your use case. Compare category fit, pricing, feature availability, and ratings before choosing.
Which tool has a free plan?
Arize Phoenix and Vellum offer a free plan based on current Toolglade data.
Where can I find alternatives?
View Arize Phoenix alternatives or view Vellum alternatives.