Vellum / vellum.ai
Platform for building, testing, evaluating, and deploying LLM applications in production with prompt management, evaluation, and monitoring capabilities.
Free plan
Yes
API access
Yes
Open source
No
Platforms
2
Vellum is a production platform for LLM applications that addresses the workflow challenges between prototyping an AI feature and running it reliably at scale. The gap between a working prompt in ChatGPT and a production-grade LLM pipeline is substantial, and Vellum provides tooling for the testing, evaluation, and deployment steps that this transition requires.
The prompt management feature allows teams to iterate on prompts without code deployments — changing a prompt, testing it against a dataset, comparing it to the previous version, and deploying the winner happens within Vellum rather than requiring engineering tickets and deployments. For product teams that want to adjust AI behaviour frequently, this operational flexibility is significant.
Evaluation and regression testing are core to Vellum's value proposition. As prompts change or models update, Vellum runs the new configuration against curated test datasets and compares performance. This catches regressions before they affect users, which is critical for applications where AI response quality is a product differentiator.
Workflow orchestration allows building multi-step LLM pipelines visually — connecting retrieval, processing, and generation steps into deployable endpoints. The visual pipeline builder reduces the code required for common AI application patterns.
Vellum competes with LangSmith and Langfuse on observability and evaluation, but differentiates with stronger focus on the full deployment workflow including prompt versioning and no-code pipeline building. Teams that want a more complete AI application platform rather than a pure observability layer will find Vellum a useful complement or alternative.
Vellum AI runs as llm application platform software built around text and code workflows. Users typically start with a prompt, upload, or connected data source, and the underlying model handles the heavy lifting before returning a result you can refine or export. It's available on web and api, with API access for teams that want to embed it into their own products.
The capabilities that matter most for teams evaluating Vellum AI.
Version-controlled prompt system allowing updates and A/B testing without engineering deployments.
Tests LLM application performance against curated datasets for regression testing when prompts or models change.
No-code interface for connecting retrieval, processing, and generation steps into deployable LLM application endpoints.
Free plan with limited usage. Pro pricing based on usage. Enterprise custom pricing. Contact Vellum for specific plan details.
Model
Freemium
Starting price
Free
Free trial
No
LangSmith from LangChain provides observability tightly integrated with LangChain. Langfuse is open source with strong self-hosting. Braintrust focuses on AI evaluation workflows. Helicone is a simpler cost-focused monitoring layer.
A side-by-side look at the closest alternative in this category.
Key facts about model providers, platforms, and team support.
Model Provider
Agnostic (OpenAI, Anthropic, etc.)
Platforms
Web, API
Deployment
SaaS
Integrations
OpenAI, Anthropic, Azure, LangChain, GitHub, Slack
Team Collaboration
No
Launch Year
2023
Compliance signals and data-handling notes as reported by the vendor.
Review Vellum's data handling policy. Prompts, test data, and production traffic are processed on Vellum's infrastructure. Enterprise includes data handling agreements.
Review Vellum's privacy policy for production traffic handling. Enterprise includes data processing agreements and potential private deployment options.
Editorial Verdict
Vellum is well-suited for product teams that need a complete AI application development and deployment platform including prompt management, testing, and monitoring. For pure observability, Langfuse or LangSmith are more focused alternatives.
Last verified July 24, 2026.
Free plan with limited usage. Pro pricing based on usage. Enterprise custom pricing. Contact Vellum for specific plan details.
Free plan with 100,000 rows of data. Usage-based on Pro with $0.00006/row logged. Enterprise custom pricing. Open source eval library available.
Review Vellum's data handling policy. Prompts, test data, and production traffic are processed on Vellum's infrastructure. Enterprise includes data handling agreements.
Review Braintrust's data handling policy. Dataset and production trace data is processed on Braintrust's infrastructure. Enterprise includes data handling agreements.
Review Vellum's privacy policy for production traffic handling. Enterprise includes data processing agreements and potential private deployment options.
Review Braintrust's privacy policy before uploading production traces containing sensitive user data. Enterprise includes comprehensive data handling agreements.
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