Baseten vs OpenAI API: who uses which
Customers, public proof and the companies that use both.
On usedby, 49 companies use Baseten and 5 use OpenAI API. 1 company uses both, including Cursor. Baseten leads among the Artificial Intelligence companies on usedby that use either tool.Latest check Oct 14, 2026: 53 of 54 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 Baseten, OpenAI API, or both
Every company with a public proof for at least one of the two tools.
48
use only Baseten
1
company uses both
4
use only OpenAI API
48 companies use only Baseten, 4 use only OpenAI API and 1 uses both, out of the 53 companies on usedby that use at least one of them.
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, Baseten | First public proof, OpenAI API |
|---|---|---|
 Cursor | On or before Dec 2025 | On or before Oct 2026 |
By industry
Which tool the companies on usedby use, by industry. Shares of the companies on usedby that use Baseten, OpenAI API or both: a share of the companies on usedby, not of the market.
Baseten onlyBothOpenAI API only
More common with Baseten
- Artificial Intelligence19 of the 19 Artificial Intelligence companies on usedby that use either tool use Baseten.
- DevTools & Infrastructure10 of the 10 DevTools & Infrastructure companies on usedby that use either tool use Baseten, 1 of them alongside OpenAI API.
- HealthTech & Digital Health6 of the 6 HealthTech & Digital Health companies on usedby that use either tool use Baseten.
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.
Baseten
OpenAI APIPricing, security and data residency are not checked yet. usedby adds them from each vendor's public pages, with the date of the check.
What customers report
Results as the vendor or the customer published them, with the source and the date.
Baseten
is projected to save us $1.9M
OpenEvidence
Vendor case study, baseten.co, published Feb 20, 2026
OpenAI API
No reviewed story for OpenAI API yet.
Questions about Baseten and OpenAI API
Which is used more, Baseten or OpenAI API?
Baseten has more customers on usedby: 49 against 5 for OpenAI API.
Do companies use both Baseten and OpenAI API?
Yes. 1 company uses both on usedby, including Cursor.
Who uses Baseten?
49 companies on usedby, each with the public page that shows it. See who uses Baseten.
Who uses OpenAI API?
5 companies on usedby, each with the public page that shows it. See who uses OpenAI API.
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 three proof levels: confirmed, 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.