LLMOps and observability
Respan: review, pricing, data and alternatives
Respan lets teams using models centralize their calls and track agent execution. It measures costs, errors, and latency, evaluates responses on test datasets, and versions model instructions. A free tier exists; the first paid plan costs $199 per month. Access and transparency score: 71/100, #7 of 18 in its category.
What is Respan?
Respan lets teams using models centralize their calls and track agent execution. It measures costs, errors, and latency, evaluates responses on test datasets, and versions model instructions.
According to its documentation, Respan lets you:
- centralize calls to multiple model providers
- track agent execution steps
- measure costs, errors, and latency
- evaluate responses on test datasets
- version instructions sent to models
- export execution logs
We file it under LLMOps and observability, the category of tools to evaluate, monitor and debug AI apps, and it also overlaps with model APIs and platforms and developer tools. The category lists 18 verified tools on this site.
The publisher is Keywords AI Inc., based in United States.
Who is it for?
It is mostly useful to these profiles: developers. The need it covers is simple to state: evaluate, monitor and debug AI apps.
Respan is a good candidate if:
- you want to try before paying
- you plan to connect it to your tools or automations through its API
Before deciding, run a trial on a real task and measure the time saved: it is the only criterion that really counts.
How much does Respan cost?
Pricing model: freemium (limited free use, then paid). A free plan is offered, usually limited in volume or features.
The first paid plan costs $199 per month (Team, billed annually; formerly Keywords AI, renamed Respan in February 2026), according to the pricing page, checked on October 24, 2026.
Per month, that is more expensive than the category median ($49 per month, based on tools with a published price).
To estimate what the same work would cost done directly with an AI model, use our API price calculator. Prices change often: always check the official site before subscribing.
Data and privacy
According to its privacy policy, data is processed in the United States.
For professional use, check that a data processing agreement (DPA) is offered, and do not send customers' personal data or confidential documents without one.
Exporting your content: JSONL, CSV. Being able to get your data back makes switching tools easier later.
Three habits apply to every AI tool:
- turn off the use of your content for training if the option exists
- use a work account separate from your personal account
- review everything the tool produces before publishing or sending it
Platforms, languages and API
Respan runs on: web browser and API.
Interface languages: English.
A public API lets you call it from your own programs or an automation tool, and plug it into an AI agent.
How we scored it
Our 71/100 score does not judge output quality: it measures what can be publicly verified about access to the tool, its openness and how far the publisher can be trusted.
| Criterion | Points | What counts |
|---|---|---|
| Access | 25/30 | free tier, published price, French interface |
| Openness | 20/30 | API, data export, open code |
| Trust | 26/40 | identified publisher, declared hosting, age, presence in reference lists |
The full calculation is explained on our method page.
Comparison with alternatives
Respan against other tools in the lLMOps and observability category:
| Tool | Free | Entry price | API | Score |
|---|---|---|---|---|
| Respan | Yes | $199 per month | Yes | 71 |
| Langfuse | Yes | $29 per month | Yes | 95 |
| LangSmith | Yes | $39 per month | Yes | 85 |
| Opik | Yes | $19 per month | Yes | 83 |
| Arize Phoenix | Yes | not published | Yes | 81 |
| Overmind | Yes | $120 per month | Yes | 78 |
| MLflow | Yes | not published | Yes | 78 |
| Prisma AIRS AI Gateway — Portkey | Yes | $49 per month | Yes | 71 |
Verdict
Respan is a decent option; compare its price and terms with the category leaders.
Strengths
- Free tier to try it
- Public API
Limitations
- More expensive than its category median
Avoid if…
- You handle sensitive personal data without a processing agreement
Alternatives
Categories and jobs
Learn more
Frequently asked questions
Is Respan free?
Yes, a free plan exists, with usage limits. The first paid plan costs $199 per month.
Where is Respan data stored?
According to the publisher, in the United States.
Does Respan have an API?
Yes, a public API is documented.
What are the alternatives to Respan?
In the same category: Langfuse, LangSmith, Opik, and Arize Phoenix.
Respan or Langfuse: which one to choose?
Respan starts at $199 per month, Langfuse at $29 per month and our score is 71/100 for Respan and 95/100 for Langfuse. Try both on the same task before paying.
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Neutrality. No affiliate links. No vendor pays to be reviewed, rated or ranked. Reviews are directed by François Chollet, neutral and factual, and every data point is dated and sourced. How we score