# Ada vs Sierra: who uses which

On usedby, 35 companies use Ada and 50 use Sierra. 1 company uses both, including GoFundMe. Counts include every proof level, job-post signals included. Companies named on both have a confirmed or observed line on each side. Latest check 2026-10-07: 77 of 85 public lines checked.

## Side by side

|  | [Ada](https://www.usedby.ai/tools/ada.md) | [Sierra](https://www.usedby.ai/tools/sierra.md) |
|---|---|---|
| Public customers | 35 | 50 |
| Confirmed | 27 | 37 |
| Observed | 8 | 13 |
| Signals (job posts) | 0 | 0 |
| Top industries of customers | Fintech & Payments (6), E-commerce & D2C (3), HR & Recruiting (3) | Fintech & Payments (5), Telecommunications (3), Banking & Mortgages (2) |
| Category | Customer Service Automation | Customer Service Automation |
| Data processing terms | — | A data processing agreement is available. ([sierra.ai](https://sierra.ai/privacy-policy), checked 2026-10-04) |

## Companies named on both

Confirmed or observed on each side. The first public proof is not an adoption date.

| Company | First public proof, Sierra |
|---|---|
| [GoFundMe](https://www.usedby.ai/companies/gofundme.md) | On or before April 2026 |

## Published results

Reviewed stories only; usedby did not measure the figures.

- Ada: [Dott](https://www.usedby.ai/case-studies/dott-ada.md): **77%**: “By 2026, that number had climbed to 77%” (published 2026-05-21)
- Ada: [Deezer](https://www.usedby.ai/case-studies/deezer-ada.md): **85%**: “Melodie is involved in about 85% of Deezer's support contacts” (published 2026-08-17)
- Sierra: [RunBuggy](https://www.usedby.ai/case-studies/runbuggy-sierra.md): **1,000 hours**: “Nearly 1,000 hours per month returned to exception handling and high-value work” (published 2026-02-03)
- Sierra: [Next](https://www.usedby.ai/case-studies/next-sierra.md): **6 weeks**: “Time to live 6 weeks” (published 2026-02-25)

---
Source: https://www.usedby.ai/compare/ada-vs-sierra · How we check: https://www.usedby.ai/methodology