Arize Phoenix vs Braintrust
Arize Phoenix vs Braintrust: side-by-side comparison of two evaluation & observability platforms systems — architecture, taxonomy, license, pricing, MCP/A2A support, and direct edges.
Cost & capability
| Arize Phoenix | Braintrust | |
|---|---|---|
| Cost tier | searched not found | searched not found |
| $/Mtok input | searched not found | searched not found |
| $/Mtok output | searched not found | searched not found |
Where they differ (9)
Rows where both sides have data and the values disagree — the shortlist of dimensions that actually distinguish these two systems.
| Arize Phoenix | Braintrust | |
|---|---|---|
| Type | OSS LLM tracing + eval | Eval + observability for AI |
| Latest release | v20.26.1 (2026-10-25) | v0.48.1 (2026-10-26) — braintrust Python SDK |
| License | Elastic-2.0 | proprietary; SDKs open source |
| GitHub | Arize-ai/phoenix — ~12.0k stars, last commit 2026-10 | searched not found |
| Pricing | searched not found | Starter $0/mo; Pro $249/mo; Enterprise custom |
| Funding | searched not found | $36M Series A 2024-04 (a16z led; $150M valuation). |
| Deployment | searched not found | Both (self-hosted + managed cloud) — hosted SaaS; on-prem deployment on Enterprise |
| API surface | Python SDK, TypeScript SDK, REST API (OpenAPI), GraphQL API, CLI (phoenix-cli) | Python SDK, TypeScript SDK, bt CLI |
| MCP | yes — built-in remote MCP server at /mcp; legacy stdio @arizeai/phoenix-mcp in maintenance | yes — Braintrust MCP server (Connect with MCP quickstart) |
At a glance
| Arize Phoenix | Braintrust | |
|---|---|---|
| Section | Evaluation & observability platforms | Evaluation & observability platforms |
| Tier | T1 | T1 |
| Type | OSS LLM tracing + eval | Eval + observability for AI |
| Created | 2023 | 2023 |
| Latest release | v20.26.1 (2026-10-25) | v0.48.1 (2026-10-26) — braintrust Python SDK |
| License | Elastic-2.0 | proprietary; SDKs open source |
| GitHub | Arize-ai/phoenix — ~12.0k stars, last commit 2026-10 | searched not found |
| Pricing | searched not found | Starter $0/mo; Pro $249/mo; Enterprise custom |
| Funding | searched not found | $36M Series A 2024-04 (a16z led; $150M valuation). |
| Deployment | searched not found | Both (self-hosted + managed cloud) — hosted SaaS; on-prem deployment on Enterprise |
| API surface | Python SDK, TypeScript SDK, REST API (OpenAPI), GraphQL API, CLI (phoenix-cli) | Python SDK, TypeScript SDK, bt CLI |
| Multi-tenancy | searched not found | searched not found |
| MCP | yes — built-in remote MCP server at /mcp; legacy stdio @arizeai/phoenix-mcp in maintenance | yes — Braintrust MCP server (Connect with MCP quickstart) |
| A2A | searched not found | searched not found |
| OpenTelemetry | searched not found | searched not found |
| Optimised for | searched not found | searched not found |
| Anti-fit | searched not found | searched not found |
Pros & cons
Arize Phoenix
Pros: searched not found
Cons: searched not found
Braintrust
Pros: searched not found
Cons: searched not found