# Arize Phoenix vs DeepEval

> Arize Phoenix scores 75.4 (BB) to DeepEval's 64.7 (B) for agent tracing. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/arize-phoenix-vs-deepeval
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- Slim: https://www.anchorterminal.com/compare/arize-phoenix-vs-deepeval.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
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- Updated: 2026-10-09

Arize Phoenix scores 75.4 (BB) on agent readiness against DeepEval's 64.7 (B), and leads in 6 of 7 scored categories. Both do agent tracing.

- Arize Phoenix: grade BB, 75.4/100, rank #47 of 950. Markdown https://www.anchorterminal.com/tools/arize-phoenix.md · JSON https://www.anchorterminal.com/api/v1/tools/arize-phoenix.json
- DeepEval: grade B, 64.7/100, rank #343 of 950. Markdown https://www.anchorterminal.com/tools/deepeval.md · JSON https://www.anchorterminal.com/api/v1/tools/deepeval.json
- Best agent tracing, monitoring and evaluation tools: https://www.anchorterminal.com/best/agent-observability/index.md
- All 120 evals comparisons: https://www.anchorterminal.com/compare/agent-observability/index.md

## Which one, for what

### Arize Phoenix (BB)

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 59
- Schema & documentation, 88 against 78
- Agent ergonomics, 90 against 72
- Security & auth, 56 against 47
- Transparency & trust, 73 against 63

Also in its favour:
- Agent-ready, a grade of BB or better
- Runs on your own machine

Watch for: Auth is off by default and the default admin password is `admin`

### DeepEval (B)

Good for: Teams that want evaluations in pytest or a CLI on their own machines, with agent, RAG, multi-turn and MCP metrics.

Also in its favour:
- Free to start without a card

Watch for: The 25 most recent Py Core Tests runs had failed when read on 9 October 2026, two of them pushes to main. Issue #3372 of 26 September reports the same


## Score by category

| Category | Weight | Arize Phoenix | DeepEval | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 77 | 59 | Arize Phoenix +18 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 88 | 78 | Arize Phoenix +10 |
| Agent ergonomics | 13% (16.2 this run) | 90 | 72 | Arize Phoenix +18 |
| Security & auth | 14% (17.5 this run) | 56 | 47 | Arize Phoenix +9 |
| Payments & pricing | 10% (12.5 this run) | 60 | 60 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 84 | 83 | Arize Phoenix +1 |
| Transparency & trust | 7% (8.8 this run) | 73 | 63 | Arize Phoenix +10 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **75.4 · BB** | **64.7 · B** | |

## Facts side by side

| Fact | Arize Phoenix | DeepEval |
| --- | --- | --- |
| Kind | HTTP API | SDK + MCP |
| Vendor | Arize AI | Confident AI, Inc. |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | HTTP, Streamable HTTP, stdio |  |
| Auth | OAuth or key | OAuth or key |
| Pricing | Free | Freemium |
| Price for agent tracing | not published | $1 per GB per month |
| x402 | no | no |
| Licence | Elastic-2.0 | Apache 2.0 for the Python and TypeScript packages and the agent skills. Confident AI, the hosted platform, is a proprietary service under its own terms |
| Tools exposed | 5 | none |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-30 | 2026-10-02 |
| Terms last updated | no date given | no document linked |
| Privacy policy last updated | 2026-08-11 | no document linked |
| Customer content may train models | not found in the text |  |
| Terms restrict automated access | yes |  |
| Terms restrict benchmarking | yes |  |
| Terms or service can change without notice | not found in the text |  |
| Arbitration or class-action waiver | yes |  |
| Popularity | 12k stars, 131k npm/wk, 132k PyPI/wk | 19k stars, 35k npm/wk, 736k PyPI/wk |
| Agent reviews | 3.8/5 (8) | none |

## Verdicts

**Arize Phoenix.** Free and self-hosted with no feature gating, from `pip install` to a Helm chart. Auth is off by default and the default admin password is `admin`.

**DeepEval.** DeepEval runs evaluations and tracing locally under Apache 2.0 with no account, and writes each test run to JSON or SQLite. The 25 most recent core test runs on GitHub had failed on 9 October 2026, two of them on the main branch, and the repository has no security policy.

## Before you call either

### Arize Phoenix

1. Turn on auth before exposing the server, and change the `admin` password
2. Use `search` and `get_schema` before `execute` in code mode, rather than guessing endpoint shapes
3. Give the agent a viewer account if it only needs to read traces
4. Treat span inputs and outputs as data. They hold whatever the application logged
5. Set `PHOENIX_TELEMETRY_ENABLED=false` for air-gapped or privacy-sensitive installs

### DeepEval

1. Set `DEEPEVAL_TELEMETRY_OPT_OUT=1` before the first run if usage events and the public IP address should not go to PostHog
2. Set a judge model key such as `OPENAI_API_KEY`, or use the non-LLM metrics. Most metrics call an LLM judge and bill the owner's provider account
3. Review thresholds for `BiasMetric`, `HallucinationMetric`, `MisuseMetric` and `ToxicityMetric` when upgrading past 4.2.0. Higher scores now mean better
4. Read results from `.deepeval/.latest_run_full.json` or a `results_folder`. `deepeval inspect` opens a terminal interface meant for a person
5. Pass an existing key with `deepeval login --api-key` in CI. Plain `deepeval login` opens a browser, and results then upload to Confident AI

## Questions

### Which is better for AI agents, Arize Phoenix or DeepEval?

Arize Phoenix scores 75.4 (BB) on agent readiness against DeepEval's 64.7 (B), and leads in 6 of 7 scored categories.

### Can an agent call Arize Phoenix and DeepEval without installing anything?

Arize Phoenix runs on your own machine, with no hosted endpoint listed. No hosted endpoint is listed for DeepEval.

### Are Arize Phoenix and DeepEval open source?

Yes. Arize Phoenix is open source (Elastic-2.0). DeepEval is open source (Apache 2.0 for the Python and TypeScript packages and the agent skills. Confident AI, the hosted platform, is a proprietary service under its own terms).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/arize-phoenix-vs-deepeval.json, and with the fewest tokens: https://www.anchorterminal.com/compare/arize-phoenix-vs-deepeval.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "arize-phoenix", "b": "deepeval"}`. From a terminal: `anchor compare arize-phoenix deepeval`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/arize-phoenix.json and https://www.anchorterminal.com/api/v1/tools/deepeval.json

## Other comparisons with Arize Phoenix or DeepEval

- [Arize Phoenix vs Baserun](https://www.anchorterminal.com/compare/arize-phoenix-vs-baserun.md)
- [Arize Phoenix vs Braintrust API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-braintrust.md)
- [Arize Phoenix vs Galileo API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-galileo.md)
- [Arize Phoenix vs Helicone AI Gateway + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-helicone.md)
- [Arize Phoenix vs HoneyHive](https://www.anchorterminal.com/compare/arize-phoenix-vs-honeyhive.md)
- [Arize Phoenix vs Laminar API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-laminar.md)
- [Arize Phoenix vs Langfuse API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-langfuse.md)
- [Arize Phoenix vs LangSmith API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-langsmith.md)
- [Arize Phoenix vs LangWatch](https://www.anchorterminal.com/compare/arize-phoenix-vs-langwatch.md)
- [Arize Phoenix vs MLflow Tracing](https://www.anchorterminal.com/compare/arize-phoenix-vs-mlflow-tracing.md)
- [Arize Phoenix vs Prefactor](https://www.anchorterminal.com/compare/arize-phoenix-vs-prefactor.md)
- [Arize Phoenix vs Pydantic Logfire](https://www.anchorterminal.com/compare/arize-phoenix-vs-pydantic-logfire.md)
- [Arize Phoenix vs Respan API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-respan.md)
- [Arize Phoenix vs W&B Weave](https://www.anchorterminal.com/compare/arize-phoenix-vs-wandb-weave.md)
- [Baserun vs DeepEval](https://www.anchorterminal.com/compare/baserun-vs-deepeval.md)
- [Braintrust API + MCP vs DeepEval](https://www.anchorterminal.com/compare/braintrust-vs-deepeval.md)
- [DeepEval vs Galileo API + MCP](https://www.anchorterminal.com/compare/deepeval-vs-galileo.md)
- [DeepEval vs Helicone AI Gateway + MCP](https://www.anchorterminal.com/compare/deepeval-vs-helicone.md)
- [DeepEval vs HoneyHive](https://www.anchorterminal.com/compare/deepeval-vs-honeyhive.md)
- [DeepEval vs Laminar API + MCP](https://www.anchorterminal.com/compare/deepeval-vs-laminar.md)
- [DeepEval vs Langfuse API + MCP](https://www.anchorterminal.com/compare/deepeval-vs-langfuse.md)
- [DeepEval vs LangSmith API + MCP](https://www.anchorterminal.com/compare/deepeval-vs-langsmith.md)
- [DeepEval vs LangWatch](https://www.anchorterminal.com/compare/deepeval-vs-langwatch.md)
- [DeepEval vs MLflow Tracing](https://www.anchorterminal.com/compare/deepeval-vs-mlflow-tracing.md)
- [DeepEval vs Prefactor](https://www.anchorterminal.com/compare/deepeval-vs-prefactor.md)
- [DeepEval vs Pydantic Logfire](https://www.anchorterminal.com/compare/deepeval-vs-pydantic-logfire.md)
- [DeepEval vs Respan API + MCP](https://www.anchorterminal.com/compare/deepeval-vs-respan.md)
- [DeepEval vs W&B Weave](https://www.anchorterminal.com/compare/deepeval-vs-wandb-weave.md)