Exa vs OpenAI API: who uses which
Customers, public proof and the companies that use both.
On usedby, 20 companies use Exa and 45 use OpenAI API. 1 company uses both, including Cursor. OpenAI API leads among the Artificial Intelligence companies on usedby that use either tool.Latest check Nov 12, 2026: 64 of 65 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 Exa, OpenAI API, or both
Every company with a public proof for at least one of the two tools.
19
listed for Exa only
1
company uses both
44
listed for OpenAI API only
On usedby, 19 companies are listed for Exa only, 44 are listed for OpenAI API only and 1 uses both, out of the 64 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 | First public proof, OpenAI API |
|---|---|
 Cursor | On or before Sep 2025 |
By industry
Which tool the companies on usedby use, by industry. Shares of the companies on usedby that use Exa, OpenAI API or both: a share of the companies on usedby, not of the market.
Listed for Exa onlyBothListed for OpenAI API only
More common with OpenAI API
- Artificial Intelligence10 of the 12 Artificial Intelligence companies on usedby that use either tool use OpenAI API.
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: Exa, 0 of 4; OpenAI API, 2 of 4. Missing facts remain unverified, not absent features.
ExaOpenAI APIWhat customers report
Results as the vendor or the customer published them, with the source and the date.
Exa
More than 9.1M Search requests to date
HockeyStack
Vendor case study, exa.ai, captured Nov 12, 2026
More than 7.2M Search requests to date: 11x uses Exa Search for high-volume prospect and account research.
11X
Vendor case study, exa.ai, captured Nov 12, 2026
OpenAI API
No reviewed story for OpenAI API yet.
Questions about Exa and OpenAI API
Which is used more, Exa or OpenAI API?
OpenAI API has more customers on usedby: 45 against 20 for Exa.
Do companies use both Exa and OpenAI API?
Yes. 1 company uses both on usedby, including Cursor.
Who uses Exa?
20 companies on usedby, each with the public page that shows it. See who uses Exa.
Who uses OpenAI API?
45 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 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.