On usedby, 35 companies use Ada and 50 use Sierra. 1 company uses both, including GoFundMe. Ada leads among the Fintech & Payments companies on usedby that use either tool.Latest check Oct 7, 2026: 77 of 85 public lines checked. Counts include every proof level, job-post signals included. Companies named on both have a confirmed or observed line on each side.
Who uses Ada, Sierra, or both
Every company with a public proof for at least one of the two tools.
34
use only Ada
1
company uses both
49
use only Sierra
34 companies use only Ada, 49 use only Sierra and 1 uses both, out of the 84 companies on usedby that use at least one of them.
Where it lands
Newest customers
We have not started tracking changes for Ada yet.
Where it lands
Newest customers
Who uses both
Companies with a confirmed or observed line on both tools.
| Company | First public proof, Sierra |
|---|---|
 GoFundMe | On or before Apr 2026 |
Side by side
Facts from our data and from each vendor's public pages. Each line says where it comes from.
Ada
SierraPricing, 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.
Ada
By 2026, that number had climbed to 77%
Dott
Vendor case study, ada.cx, published May 21, 2026
Melodie is involved in about 85% of Deezer's support contacts
Deezer
Vendor case study, ada.cx, published Aug 17, 2026
Sierra
Nearly 1,000 hours per month returned to exception handling and high-value work
RunBuggy
Vendor case study, sierra.ai, published Feb 3, 2026
Questions about Ada and Sierra
Which is used more, Ada or Sierra?
Sierra has more customers on usedby: 50 against 35 for Ada.
Do companies use both Ada and Sierra?
Yes. 1 company uses both on usedby, including GoFundMe.
Who uses Ada?
35 companies on usedby, each with the public page that shows it. See who uses Ada.
Who uses Sierra?
50 companies on usedby, each with the public page that shows it. See who uses Sierra.
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 is named as using both tools when its lines on both are confirmed or observed.