Vellum
by Vellum AI
LLM application platform with prompt management, evaluation, and deployment workflows for production AI features. Vellum is an LLM application development platform founded in 2023 in San Francisco. The product targets engineering teams that need versioned prompts, evaluation pipelines, and deployment infrastructure for shipping AI features into production applications.
Performance Scores
1 ranking evaluated
Score range: 8.4 – 8.4
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#1Best LLM App Platforms for Building AI Agents in 2026
Score: 8.4 · Best for: Product and ML teams shipping evaluated LLM features into production at mid-market and enterprise scale.
Key Facts
| Attribute | Value | As of | Source |
|---|---|---|---|
| Pricing | Pro plan approximately $500/month, Developer tier free, Enterprise custom | Apr 2026 | Vellum |
| Capabilities | Prompt IDE, Evaluations, Workflows, Deployments, RAG indexes (5 modules) | Apr 2026 | Vellum docs |
| Founded | 2023 | Apr 2026 | Y Combinator |
| Key Differentiator | Y Combinator W23 alumnus focused on prompt evaluation and regression testing for production LLM apps | Apr 2026 | Vellum |
Strengths
- ●Built-in evaluation harness with human review and regression testing
- ●Production-grade prompt versioning and rollout controls
- ●SOC 2 Type II with audit logs and RBAC
- ●Multi-model routing across OpenAI, Anthropic, Google, and self-hosted endpoints
Limitations
- ●Pricing oriented to mid-market and enterprise — limited free tier
- ●Lighter on prebuilt SaaS connectors than agent-first platforms
- ●Workflow visual builder is less mature than dedicated agent builders
Based on evaluations in 1 ranking: Best LLM App Platforms for Building AI Agents in 2026
About Vellum
Vellum is an LLM application development platform founded in 2023 in San Francisco. The product targets engineering teams that need versioned prompts, evaluation pipelines, and deployment infrastructure for shipping AI features into production applications.
The platform combines a Prompt IDE for testing variants across providers (OpenAI, Anthropic, Google, Azure), an Evaluation suite for regression testing prompt changes against test cases, a Workflows visual builder for chaining LLM calls with code, retrieval, and conditional logic, and a Deployments layer with versioning, monitoring, and request logs. Vellum supports retrieval-augmented generation through managed vector indexes and integrates with customer-supplied embeddings. Pricing starts with a free Developer tier (limited requests), with paid Pro plans approximately $500/month and Enterprise pricing custom-quoted as of public docs in April 2026.
Integrations (4)
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AI Agent PlatformsSee How It Ranks
Best AI Agent Builders for Non-Developers in 2026
A ranked list of the best AI agent builders for non-developers in 2026. This ranking evaluates platforms that let operations, marketing, and customer-success teams construct multi-step AI agents without writing production code. The shortlist includes Lindy, Gumloop, Relay.app, Relevance AI, and Dust. Tools were evaluated on visual agent design, model and tool integration, observability and debugging, pricing accessibility, and documentation depth. Stack AI and Magic Loops were considered but excluded where the platform was not present in the database at evaluation time.
Best LLM App Platforms for Building AI Agents in 2026
A ranked list of platforms for building LLM-powered applications and AI agents in 2026. This ranking covers tools that combine prompt engineering, model orchestration, retrieval-augmented generation, tool calling, and deployment into a single workflow for product and engineering teams. Entries span low-code agent builders (Gumloop, Lindy, Relevance AI), code-first orchestration (CrewAI), open-source visual builders (Langflow), enterprise prompt engineering platforms (Vellum), and team-oriented agent suites (Dust). Scoring reflects developer experience, model and integration breadth, pricing, governance posture, and runtime reliability.
Questions About Vellum
What is the best LLM app platform in 2026?
As of April 2026, the leading LLM app platforms are LangChain (most-used Python and JS framework), Vellum (production prompt and eval platform), Langflow (open-source visual builder), Dust (workspace assistants), and LlamaIndex (data-framework for RAG). Choice depends on visual versus code preference and whether teams need eval, RAG, or workspace assistants.
What are the best Langflow alternatives in 2026?
As of April 2026, the leading Langflow alternatives are Flowise (open-source LangChain UI), LangChain itself (code-first SDK), Vellum (production prompt and eval platform), n8n with AI nodes (general workflow plus LLM steps), and CrewAI (multi-agent orchestration in Python). Choice depends on visual versus code preference and whether teams need agents or chains.
What are the best Vellum alternatives in 2026?
As of April 2026, the leading Vellum alternatives are Langflow (open-source visual LangChain builder), LangSmith (LangChain observability and eval), Dust (workspace-grade AI assistants), Relevance AI (low-code AI agents), and Humanloop (prompt management and evaluation). Selection depends on whether teams need prompt eval, agent orchestration, or production deployment.
What are the best Dust alternatives in 2026?
As of April 2026, the leading Dust alternatives are Relevance AI (low-code AI workforce), Lindy (personal AI assistants), Gumloop (visual AI workflows), Relay.app (human-in-the-loop automations), and Glean (enterprise search and assistants). Choice depends on whether teams want internal assistants, agent workforces, or workflow automation.