Mistral vs OpenAI API: who uses which
Customers, public proof and the companies that use both.
On usedby, 42 companies use Mistral and 37 use OpenAI API. 1 company uses both, including Cisco. Mistral leads among the Banking & Mortgages companies on usedby that use either tool, OpenAI API among the DevTools & Infrastructure companies.Latest check Oct 18, 2026: 77 of 79 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 Mistral, OpenAI API, or both
Every company with a public proof for at least one of the two tools.
41
use only Mistral
1
company uses both
36
use only OpenAI API
41 companies use only Mistral, 36 use only OpenAI API and 1 uses both, out of the 78 companies on usedby that use at least one of them.
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 |
|---|---|
 Cisco | On or before Oct 2026 |
By industry
Which tool the companies on usedby use, by industry. Shares of the companies on usedby that use Mistral, OpenAI API or both: a share of the companies on usedby, not of the market.
Mistral onlyBothOpenAI API only
More common with Mistral
- Banking & Mortgages4 of the 6 Banking & Mortgages companies on usedby that use either tool use Mistral.
More common with OpenAI API
- DevTools & Infrastructure6 of the 7 DevTools & Infrastructure 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.
MistralOpenAI APIWhat customers report
Results as the vendor or the customer published them, with the source and the date.
Mistral
With over 30% of French general practitioners and 300 hospitals relying on Synapse
Synapse Medicine
Vendor case study, mistral.ai, published Apr 24, 2026
The Groupe SNCF GPT has been deployed to over 100,000 employees
SNCF
Vendor case study, mistral.ai, published Apr 24, 2026
OpenAI API
No reviewed story for OpenAI API yet.
Questions about Mistral and OpenAI API
Which is used more, Mistral or OpenAI API?
Mistral has more customers on usedby: 42 against 37 for OpenAI API. Mistral leads among the Banking & Mortgages companies on usedby that use either tool, OpenAI API among the DevTools & Infrastructure companies.
Do companies use both Mistral and OpenAI API?
Yes. 1 company uses both on usedby, including Cisco.
Who uses Mistral?
42 companies on usedby, each with the public page that shows it. See who uses Mistral.
Who uses OpenAI API?
37 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.