Vellum
llm-observability
Build, evaluate, and deploy LLM apps and agents with confidence.
Pricing
Free plan
Rating
—
Votes
0
Head-to-head comparison
Vellum vs Opik
Compare Vellum and Opik side by side across pricing, features, ratings, pros, cons, best-fit use cases, and alternatives.
Opik
llm-observability
Open-source LLM evaluation, tracing, and observability by Comet.
Pricing
Free plan
Rating
—
Votes
0
Feature comparison
Feature
Vellum
Opik
Category
llm-observability
llm-observability
Pricing
Free plan
Free plan
Free plan
API access
Mobile app
Browser extension
Team collaboration
Custom training
Self-hosted option
Offline mode
Multi-language support
Vellum pros and cons
Combines prompt, workflow, evaluation, and deployment in one platform
Visual workflow builder lowers the barrier for cross-functional collaborators
Solid evaluation and testing tooling for pre-production quality gates
Multi-provider model support avoids lock-in
Pricing is opaque and sales-led, making budgeting hard
Not open source, and self-hosting is locked to Enterprise
Free tier is quite limited in credits, documents, and seats
Opik pros and cons
Full platform is Apache-2.0 and free to self-host
Combines tracing and evaluation in one tool
LLM-as-a-judge and many automated metrics
Fast-growing, widely adopted open-source project
Crowded, competitive category
Self-hosting requires running infrastructure
Managed cloud limits (spans, seats) on lower tiers
Which one should you choose?
Best overall signal
Vellum
Selected using Toolglade popularity signals such as views and votes.
Best value signal
Vellum
Selected using free-plan availability and engagement signals.
Best for
Vellum
- collaborative agent building
- prompt evaluation and testing
- deploying LLM features
- cross-functional AI teams
- Teams wanting an all-in-one build-evaluate-deploy platform
Opik
- LLM evaluation
- agent tracing
- prompt management
- production LLM monitoring
- Teams wanting open-source eval plus tracing
FAQ
Is Vellum better than Opik?
It depends on your use case. Compare category fit, pricing, feature availability, and ratings before choosing.
Which tool has a free plan?
Vellum and Opik offer a free plan based on current Toolglade data.