Best Respan (formerly Keywords AI) Alternatives in 2026
15 LLM observability tools our editors would look at instead of Respan (formerly Keywords AI), in our ranking order.
Respan (formerly Keywords AI): A broad observability and gateway platform for enterprise LLM and agent teams. Where it falls short: team access starts at $199 per month with annual billing.
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Best forTeams wanting broad, production-ready LLM observability
Broad LLM observability with tracing, evaluations, prompts, agents, RAG, and cost tracking.
- LLM evaluations
- Prompt management
- Retrieval tracing
9.0/10★★★★☆Visit Arize AX -
Best forTeams seeking balanced open-source observability
A broad observability platform with open-source deployment and accessible paid tiers.
- LLM evaluations
- Prompt management
- Retrieval tracing
9.0/10★★★★☆Visit Langfuse -
Best forDevelopers wanting free open-source LLM observability
A free platform for tracing, evaluating, and improving LLM applications.
- LLM evaluations
- Prompt management
- Retrieval tracing
9.0/10★★★★☆Visit Arize Phoenix -
Best forCost-conscious teams needing full-stack observability
A broad, cost-conscious stack for tracing, evaluation, prompts, monitoring, and agent debugging.
- LLM evaluations
- Prompt management
- Retrieval tracing
9.0/10★★★★☆Visit Opik -
Best forGrowing teams wanting mature, broad observability
A broad observability suite for teams tracing, evaluating, and monitoring LLM applications.
- LLM evaluations
- Prompt management
- Retrieval tracing
10.0/10★★★★★Visit W&B Weave -
Best forLangChain-centric teams needing an integrated platform
A broad LLM observability platform with especially strong LangChain ecosystem fit.
- LLM evaluations
- Prompt management
- Retrieval tracing
9.0/10★★★★☆Visit LangSmith -
Best forTeams needing affordable agent and RAG visibility
Affordable visibility for agents, RAG pipelines, evaluations, and LLM costs.
- LLM evaluations
- Prompt management
- Retrieval tracing
9.0/10★★★★☆Visit LangWatch -
Best forDevelopers focused on deep trace investigation
A broad observability platform for tracing agents, costs, failures, and evaluations.
- LLM evaluations
- Prompt management
- Retrieval tracing
9.0/10★★★★☆Visit Laminar -
Best forTeams wanting observability plus an LLM gateway
A broad LLM monitoring stack with gateway, tracing, evaluations, and self-hosting.
- LLM evaluations
- Prompt management
- Retrieval tracing
10.0/10★★★★★Visit Helicone -
Best forOrganizations prioritizing guardrails and governance
A governance-focused observability platform for LLMs, agents, retrieval, and predictive models.
- LLM evaluations
- Prompt management
- Retrieval tracing
9.0/10★★★★☆Visit Fiddler AI -
Best forSelf-hosting teams needing broad infrastructure visibility
A broad observability stack for teams comfortable running AI infrastructure themselves.
- LLM evaluations
- Prompt management
- Retrieval tracing
9.0/10★★★★☆Visit OpenLIT -
Best forTeams wanting extensive agent-framework coverage
A broad observability and evaluation suite for teams building LLM agents.
- LLM evaluations
- Prompt management
- Retrieval tracing
8.0/10★★★★☆Visit HoneyHive -
Best forAgent teams needing replay and audit visibility
A focused observability platform for replay, debugging, cost tracking, and audit visibility.
- Retrieval tracing
- Token cost tracking
- LLM tracing
7.7/10★★★★☆Visit AgentOps -
Evidently AI not yet scored
Best forOpen-source teams focused on evaluation and monitoring
A broad open-source toolkit for evaluating, tracing, and monitoring LLM applications.
- LLM evaluations
- Prompt management
- LLM tracing
—not yet scoredVisit Evidently AI -
Best forEvaluation-led teams needing production observability
A broad evaluation and tracing platform for teams operating LLM and agent workflows.
5.0/10★★☆☆☆Visit Galileo
Respan (formerly Keywords AI) Alternatives: Common Questions
What is the best alternative to Respan (formerly Keywords AI)?
Arize AX: #1 in our LLM Observability Tools ranking, with an editor score of 9.0 out of 10. Broad LLM observability with tracing, evaluations, prompts, agents, RAG, and cost tracking.
Is there a free alternative to Respan (formerly Keywords AI)?
Yes. Arize AX, Langfuse, Arize Phoenix, Opik and W&B Weave have a free plan or a free tier (15 of the 15 alternatives on this page).
What is the cheapest paid alternative to Respan (formerly Keywords AI)?
Of the alternatives here that publish a price, Opik starts lowest, at $19/mo.
Respan (formerly Keywords AI) vs Each Alternative
| # | Tool | Free plan | Paid from | LLM tracing | LLM evaluations | Prompt management | Agent tracing | Retrieval tracing | Deployment options | Score |
|---|---|---|---|---|---|---|---|---|---|---|
| 22 | Respan (formerly Keywords AI) | Yes | $199/mo | Yes | Yes | Yes | Yes | Yes | Both | 9.0 |
| 1 | Arize AX | Yes | $50/mo | Yes | Yes | Yes | Yes | Yes | Both | 9.0 |
| 2 | Langfuse | Yes | $29/mo | Yes | Yes | Yes | Yes | Yes | Both | 9.0 |
| 3 | Arize Phoenix | Yes | None | Yes | Yes | Yes | Yes | Yes | Both | 9.0 |
| 4 | Opik | Yes | $19/mo | Yes | Yes | Yes | Yes | Yes | Both | 9.0 |
| 5 | W&B Weave | Yes | $60/mo | Yes | Yes | Yes | Yes | Yes | Both | 10.0 |
| 6 | LangSmith | Yes | — | Yes | Yes | Yes | Yes | Yes | Both | 9.0 |
| 7 | LangWatch | Yes | — | Yes | Yes | Yes | Yes | Yes | Both | 9.0 |
| 8 | Laminar | Yes | $30/mo | Yes | Yes | Yes | Yes | Yes | Both | 9.0 |
| 9 | Helicone | Yes | $79/mo | Yes | Yes | Yes | Yes | Yes | Both | 10.0 |
| 10 | Fiddler AI | Yes | — | Yes | Yes | Yes | Yes | Yes | Both | 9.0 |
| 11 | OpenLIT | Yes | None | Yes | Yes | Yes | Yes | Yes | Self_hosted | 9.0 |
| 12 | HoneyHive | Yes | — | Yes | Yes | Yes | Yes | Yes | Both | 8.0 |
| 13 | AgentOps | Yes | $40/mo | Yes | — | — | Yes | Yes | Both | 7.7 |
| not scored | Evidently AI | Yes | None | Yes | Yes | Yes | Yes | — | Both | — |
| 15 | Galileo | Yes | $100/mo | — | — | — | — | — | Both | 5.0 |
Reviewed by iTechGuides Editors · Editorial team · Updated Sep 2026