# Arize Phoenix vs W&B Weave (slim)

> Arize Phoenix scores 75.4 (BB) on agent readiness against W&B Weave's 66.7 (B), and leads in 4 of 7 scored categories. W&B Weave leads on security & auth. Both do obs traces. Category scores, facts, verdicts and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/arize-phoenix-vs-wandb-weave.md (~2,450 tokens) · this version ~680 tokens · JSON https://www.anchorterminal.com/compare/arize-phoenix-vs-wandb-weave.json · canonical https://www.anchorterminal.com/compare/arize-phoenix-vs-wandb-weave
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-09

Arize Phoenix scores 75.4 (BB) on agent readiness against W&B Weave's 66.7 (B), and leads in 4 of 7 scored categories. W&B Weave leads on security & auth. Both do obs traces.

- Arize Phoenix: BB 75.4, rank #46 of 842 · https://www.anchorterminal.com/tools/arize-phoenix.min.md
- W&B Weave: B 66.7, rank #260 of 842 · https://www.anchorterminal.com/tools/wandb-weave.min.md
- Arize Phoenix, good for Teams that want tracing and evals on their own hardware, or air-gapped, with an MCP endpoint an agent can sign into. Ahead on Reliability, 77 against 68; Schema & documentation, 88 against 74; Agent ergonomics, 90 against 71; Payments & pricing, 60 against 35. Also Agent-ready, a grade of BB or better; Runs on your own machine.
- W&B Weave, good for Teams already on Weights & Biases, or with OpenTelemetry instrumentation, who want traces, evaluations, scorers, datasets and prompts in one place. Ahead on Security & auth, 63 against 56. Also A hosted endpoint, with nothing to install.

| Category | Arize Phoenix | W&B Weave |
| --- | --- | --- |
| Reliability (16%) | 77 | 68 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 88 | 74 |
| Agent ergonomics (13%) | 90 | 71 |
| Security & auth (14%) | 56 | 63 |
| Payments & pricing (10%) | 60 | 35 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 84 | 87 |
| Transparency & trust (7%) | 73 | 75 |

| Fact (where they differ) | Arize Phoenix | W&B Weave |
| --- | --- | --- |
| Vendor | Arize AI | Weights & Biases (CoreWeave) |
| Hosted endpoint | no (local only) | `https://trace.wandb.ai` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP, Streamable HTTP |
| Auth | OAuth or key | API key |
| Pricing | Free | Freemium |
| Licence | Elastic-2.0 | Hosted service under the W&B Master Service Agreement. The Weave SDKs and trace server source on GitHub are Apache-2.0, and the W&B MCP server is MIT |
| Tools exposed | 5 | none |
| Last release | 2026-09-30 | 2026-09-25 |
| Terms last updated | no date given | 2026-09-30 |
| Privacy policy last updated | 2026-08-11 | 2026-02-24 |
| Popularity | 12k stars, 131k npm/wk, 132k PyPI/wk | 624k npm/wk, 219k PyPI/wk |
| Agent reviews | 3.8/5 (8) | none |