Langfuse vs Speakeasy: who uses which
Customers, public proof and the companies that use both.
On usedby, 17 companies use Langfuse and 47 use Speakeasy. 1 company uses both, including Cisco. Langfuse leads among the Fintech & Payments companies on usedby that use either tool, Speakeasy among the DevTools & Infrastructure companies.Latest check Nov 12, 2026: 64 of 64 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 Langfuse, Speakeasy, or both
Every company with a public proof for at least one of the two tools.
16
listed for Langfuse only
1
company uses both
46
listed for Speakeasy only
On usedby, 16 companies are listed for Langfuse only, 46 are listed for Speakeasy only and 1 uses both, out of the 63 companies listed for at least one. An absent listing does not prove non-use.
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 |
|---|
 Cisco |
By industry
Which tool the companies on usedby use, by industry. Shares of the companies on usedby that use Langfuse, Speakeasy or both: a share of the companies on usedby, not of the market.
Listed for Langfuse onlyBothListed for Speakeasy only
More common with Langfuse
- Fintech & Payments4 of the 7 Fintech & Payments companies on usedby that use either tool use Langfuse.
More common with Speakeasy
- DevTools & Infrastructure8 of the 9 DevTools & Infrastructure companies on usedby that use either tool use Speakeasy.
- Artificial Intelligence5 of the 7 Artificial Intelligence companies on usedby that use either tool use Speakeasy.
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: Langfuse, 0 of 5; Speakeasy, 3 of 5. Missing facts remain unverified, not absent features.
LangfuseSpeakeasyWhat customers report
Results as the vendor or the customer published them, with the source and the date.
Langfuse
No reviewed story for Langfuse yet.
Speakeasy
We had one developer spending at least 5 hours/week generating new SDKs for every API release.
Formance
Vendor case study, speakeasy.com, captured Nov 12, 2026
8X reduction in expected cost of Terraform Provider
Epilot
Vendor case study, speakeasy.com, captured Nov 12, 2026
Questions about Langfuse and Speakeasy
Which is used more, Langfuse or Speakeasy?
Speakeasy has more customers on usedby: 47 against 17 for Langfuse. Langfuse leads among the Fintech & Payments companies on usedby that use either tool, Speakeasy among the DevTools & Infrastructure companies.
Do companies use both Langfuse and Speakeasy?
Yes. 1 company uses both on usedby, including Cisco.
Who uses Langfuse?
17 companies on usedby, each with the public page that shows it. See who uses Langfuse.
Who uses Speakeasy?
47 companies on usedby, each with the public page that shows it. See who uses Speakeasy.
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.