kitio.aiLangfuse vs TruLens
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. TruLens is completely free, while Langfuse is freemium.
At a glance
Best for
Category
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- LLM tracing
- OpenTelemetry support
- Prompt management
- Evaluations and datasets
- Self-hosting
- OpenTelemetry tracing
- LLM judge evaluations
- RAG triad metrics
- Custom rubrics
- Multi-turn conversation evals
| Feature | Langfuse | TruLens |
|---|---|---|
| Best for | Open-source LLM observability, prompt management and evals | Open-source evals and OpenTelemetry tracing for AI agents and RAG |
| Category | Models & APIs | Models & APIs |
| Pricing model | Freemium | Free |
| Starting price | $29/mo | Free |
| Free plan | Yes | Yes, fully free |
| Made by | ClickHouse | Snowflake |
| Based in | United States | United States |
| Rating | No ratings yet | No ratings yet |
| Key features |
|
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Pricing compared
TruLens is completely free, while Langfuse is freemium.
Free plan
Cheapest paid plan
Top plan
Free trial
4 plans
Hobby
Free
- Free cloud plan
- Limited usage and history
Core
$29/mo
- 100k units included, $8/100k extra
- 90 days data access
- Unlimited users
Pro
$199/mo
- 3 years data access
- High rate limits
- SOC2 and ISO27001 reports
Enterprise
$2499/mo
- Audit logs and SCIM API
- Uptime and support SLA
- Named support engineer
Prices in USD, checked Oct 28, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
Langfuse
- Free to self-host
- No seat-based fees
- Works with any framework
- Self-hosting needs ops work
- Advanced features on paid tiers
- UI can feel dense
TruLens
- Free and open source
- Judges explain each score
- Standard OpenTelemetry traces
- Python library, not a hosted product
- Judge scoring adds LLM costs
- Custom metrics require writing code
Which one should you choose?
Choose Langfuse if you want:
- Free to self-host
- No seat-based fees
- Works with any framework
Watch out: self-hosting needs ops work.
Choose TruLens if you want:
- Free and open source
- Judges explain each score
- Standard OpenTelemetry traces
Watch out: python library, not a hosted product.
Langfuse vs TruLens FAQ
What is the difference between Langfuse and TruLens?
Langfuse: Open-source LLM observability, prompt management and evals. TruLens: Open-source evals and OpenTelemetry tracing for AI agents and RAG. Both are models & apis tools.
Is Langfuse or TruLens cheaper?
TruLens is completely free, while Langfuse is freemium.
Do Langfuse and TruLens have free plans?
Langfuse: Yes. TruLens: Yes, fully free.
Who makes Langfuse?
Langfuse is made by ClickHouse, based in United States.
Who makes TruLens?
TruLens is made by Snowflake, based in United States.
Which should I choose, Langfuse or TruLens?
Choose Langfuse if you value free to self-host and no seat-based fees. Choose TruLens if you value free and open source and judges explain each score.