Langfuse vs Weights & Biases
Which Developer Tools AI tool is better in 2026?
Langfuse
Open source LLM engineering platform for debugging, analyzing, and iterating on LLM applications
Weights & Biases
The AI developer platform
Side-by-side
Weights & Biases is the more established option (raised $245M), but Langfuse is cheaper to start.
| Metric | Langfuse | Weights & Biases |
|---|---|---|
| Taglinei | Open source LLM engineering platform for debugging, analyzing, and iterating on LLM applications | The AI developer platform |
| Foundedi | 2023 | 2018🏆 |
| HQi | DE | San Francisco, US |
| Employeesi | 11-50 | 500-1000🏆 |
| Neuron scorei | 52🏆 | 50 |
| Total fundingi | $8M | $245M🏆 |
| Latest roundi | Seed · Nov 2023 | Series C · Oct 2023 |
| Valuationi | — | $1B🏆 |
| Cheapest paid plani | From $29/mo🏆 | — |
| Free plani | ✓ | ✗ |
| Free triali | ✗ | ✗ |
| Top tier pricei | Pricing not disclosed | Enterprise · Contact sales |
| Pricing summaryi | Free · From $29/mo | 1 published plans |
| Categoriesi |
Capability matrix
Developer-facing capabilities and access signals for Langfuse and Weights & Biases.
| Capability | Langfuse | Weights & Biases |
|---|---|---|
| MCP support | ✗ | ✗ |
| Public API | ✗ | ✓ |
| Webhooks | ✗ | ✗ |
| OAuth 2.0 | ✗ | ✗ |
| SDK languages | 3 (Python, JavaScript, TypeScript) | 1 (Python) |
| Free plan | ✓ | ✗ |
| Free trial | ✗ | ✗ |
| Verified | ✗ | ✓ |
| Active deal | ✗ | ✗ |
🟢 Strengths of Langfuse
- Higher Neuron score (52 vs 50)
- Offers a free plan
- Lower starting price ($29/mo)
- Newer company (2023)
🔵 Strengths of Weights & Biases
- Has raised more capital ($245M vs $8M)
- More mature (2018)
- Verified profile
Which should you choose?
Choose Langfuse if price matters most — it starts at Free · From $29/mo, which is friendlier for teams watching burn. Both AI Developer Tools tools ship core features, so the cost delta often decides it for small teams and solo operators.
Choose Weights & Biases if you want the most established option — it has raised $245M, suggesting more runway for enterprise features, support, and long-term roadmap. For mission-critical workflows or larger teams, that stability often outweighs a lower monthly price.
Frequently asked questions
Langfuse vs Weights & Biases — which is better?
It depends on your priority. Langfuse is the leaner option; Weights & Biases has broader feature depth. See the side-by-side table above.
Is Langfuse cheaper than Weights & Biases?
Yes — Langfuse's cheapest paid plan is Free · From $29/mo, while Weights & Biases's is Enterprise · Contact sales.
Do Langfuse and Weights & Biases offer free plans?
Langfuse: Yes, has a free plan. Weights & Biases: Paid only.
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