Braintrust vs Langfuse: who uses which
Customers, public proof and the companies that use both.
On usedby, 41 companies use Braintrust and 17 use Langfuse. 1 company uses both, including Samsara. Braintrust leads among the DevTools & Infrastructure companies on usedby that use either tool, Langfuse among the Fintech & Payments companies.Latest check Nov 12, 2026: 58 of 58 public lines checked. Counts include every proof level, job-post signals included. A company on both tools counts at any proof level, and a job post on one side is marked as such.
Who uses Braintrust, Langfuse, or both
Every company with a public proof for at least one of the two tools.
40
listed for Braintrust only
1
company uses both
16
listed for Langfuse only
On usedby, 40 companies are listed for Braintrust only, 16 are listed for Langfuse only and 1 uses both, out of the 57 companies listed for at least one. An absent listing does not prove non-use.
Where it lands
Recently publicly listed customers
Who uses both
Companies with a public line on both tools, at any proof level: the strongest proofs come first, and a job post is marked.
| Company | First public proof, Braintrust |
|---|---|
 Samsara | On or before Oct 2026 |
By industry
Which tool the companies on usedby use, by industry. Shares of the companies on usedby that use Braintrust, Langfuse or both: a share of the companies on usedby, not of the market.
Listed for Braintrust onlyBothListed for Langfuse only
More common with Braintrust
- DevTools & Infrastructure12 of the 13 DevTools & Infrastructure companies on usedby that use either tool use Braintrust.
- Artificial Intelligence5 of the 7 Artificial Intelligence companies on usedby that use either tool use Braintrust.
More common with Langfuse
- Fintech & Payments4 of the 7 Fintech & Payments companies on usedby that use either tool use Langfuse.
Source: every usedby line, from confirmed proofs to job-post signals (the weakest proof level).
Side by side
Facts from our data and from each vendor's public pages. Each line says where it comes from.
Vendor facts checked: Braintrust, 4 of 6; Langfuse, 0 of 6. Missing facts remain unverified, not absent features.
BraintrustLangfuseWhat customers report
Results as the vendor or the customer published them, with the source and the date.
Braintrust
100,000s of public eval dashboard views
Browserbase
Vendor case study, braintrust.dev, captured Nov 10, 2026
Continuous signal, 30-min fix cycles
Rex
Vendor case study, braintrust.dev, captured Nov 10, 2026
Langfuse
No reviewed story for Langfuse yet.
Questions about Braintrust and Langfuse
Which is used more, Braintrust or Langfuse?
Braintrust has more customers on usedby: 41 against 17 for Langfuse. Braintrust leads among the DevTools & Infrastructure companies on usedby that use either tool, Langfuse among the Fintech & Payments companies.
Do companies use both Braintrust and Langfuse?
Yes. 1 company uses both on usedby, including Samsara.
Who uses Braintrust?
41 companies on usedby, each with the public page that shows it. See who uses Braintrust.
Who uses Langfuse?
17 companies on usedby, each with the public page that shows it. See who uses Langfuse.
How does usedby count customers?
A company counts when a public page shows it: a vendor's customer page, a case study, a press release or a job post, most saved with a dated capture. Every line is a customer, at one of four proof levels: confirmed, declared by the company itself, observed or signal (a job post, the weakest). A company counts as using both tools when it has a line on each, at any level; the list shows the strongest proofs first and marks job posts.