Arize AI vs LangWatch
Which Evaluation AI tool is better in 2026?
Arize AI
The AI & Agent Engineering Platform for development, observability, and evaluation of LLM applications.
LangWatch
Platform for LLM evaluations, agent testing and observability
Side-by-side
Arize AI is the more established option (raised $132M); pricing is comparable on both sides.
| Metric | Arize AI | LangWatch |
|---|---|---|
| Taglinei | The AI & Agent Engineering Platform for development, observability, and evaluation of LLM applications. | Platform for LLM evaluations, agent testing and observability |
| Foundedi | — | 2023🏆 |
| HQi | — | Amsterdam, NL |
| Employeesi | — | 1-10🏆 |
| Neuron scorei | 17 | 60🏆 |
| Total fundingi | $132M🏆 | $1.1M |
| Latest roundi | Series C · Feb 2024 | Pre-Seed · Jan 2024 |
| Valuationi | — | — |
| Cheapest paid plani | — | Pricing not disclosed |
| Free plani | ✗ | ✓ |
| Free triali | ✗ | ✗ |
| Top tier pricei | Enterprise · Contact sales | Pricing not disclosed |
| Pricing summaryi | 1 published plans | Open source |
| Categoriesi |
Capability matrix
Developer-facing capabilities and access signals for Arize AI and LangWatch.
| Capability | Arize AI | LangWatch |
|---|---|---|
| MCP support | ✗ | ✗ |
| Public API | ✗ | ✓ |
| Webhooks | ✗ | ✗ |
| OAuth 2.0 | ✗ | ✗ |
| SDK languages | 1 (Python) | — |
| Free plan | ✗ | ✓ |
| Free trial | ✗ | ✗ |
| Verified | ✗ | ✗ |
| Active deal | ✗ | ✗ |
🟢 Strengths of Arize AI
- Has raised more capital ($132M vs $1.1M)
🔵 Strengths of LangWatch
- Higher Neuron score (60 vs 17)
- Offers a free plan
- Newer company (2023)
Which should you choose?
Choose LangWatch if price matters most — it starts at Open source, which is friendlier for teams watching burn. Both AI Evaluation tools ship core features, so the cost delta often decides it for small teams and solo operators.
Choose Arize AI if you want the most established option — it has raised $132M, suggesting more runway for enterprise features, support, and long-term roadmap. For mission-critical workflows or larger teams, that stability often outweighs a lower monthly price.
Frequently asked questions
Arize AI vs LangWatch — which is better?
It depends on your priority. Arize AI has raised more capital and is the more established option; LangWatch has broader feature depth. See the side-by-side table above.
Is Arize AI cheaper than LangWatch?
No — LangWatch's cheapest paid plan is Open source, while Arize AI's is Enterprise · Contact sales.
Do Arize AI and LangWatch offer free plans?
Arize AI: Paid only. LangWatch: Yes, has a free plan.
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