80
Stack Score
Editorial pick✓ Verified working
Vellum
LLM development platform with eval and observability
Try Vellum✓ Free trial available
Best for
Best for solo-agency engineering teams shipping LLM features who need prompt management, eval, and observability.
At a glance
- Pricing
- enterprise
- Setup time
- 1 hour
- Learning curve
- medium
- Last verified
- 5/25/2026
What we love
- ✓Strong eval framework — actually useful before production
- ✓Multi-provider support without lock-in
- ✓Active development pace
Where it falls short
- −Pricing requires sales contact above the entry tier
- −Smaller integration library than LangSmith
- −UX has some rough edges
Pricing
✓ Pricing verified Jun 21, 20263 tiers
Free Trial
$0
14 days
- ✓Sandbox
- ✓Limited usage
Pro
Contact
per month
- ✓Production deployment
- ✓Eval suites
- ✓Observability
Enterprise
Custom
annual contract
- ✓SSO
- ✓Custom SLA
- ✓Dedicated support
Why we picked it
If you're shipping an LLM feature into production, Vellum's eval and monitoring layers are worth the price. — MoreAI.tools editor
Overview
Vellum is a development platform for production LLM features — prompt engineering, evaluation, deployment, monitoring. Used by engineering teams building real AI products.
Key features
- ●Prompt sandbox with model comparison
- ●Eval framework with test suites
- ●Production observability and tracing
- ●RAG pipeline builder
- ●Workflow engine for multi-step chains
Best use cases
Connect siloed apps
Sync customer, billing, or task data across the SaaS stack on a recurring schedule.
Document or data extraction
Pull structured fields out of PDFs, emails, or web pages and route them to a system of record.
Integrations
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