Agents capable of making and receiving phone calls
213 companies on usedby use at least one of the 11 tools in this category with a public customer. Regal leads with 40 companies. Then come Retell AI (32) and Hippocratic AI (28). 3 companies run two of these tools or more. The most common pair is Bland AI with Regal (1 company).Latest check Oct 8, 2026: 208 of 216 public lines checked. Counts are of companies on usedby, not of the whole market: we list a company when a public page shows its AI tools.
213
companies on usedby use a tool of this category
Companies per tool. A company using two tools counts for both.
Counts include job-post signals, drawn apart on each tool page.
Companies with a public line for each tool. Job-post signals count and are drawn apart in the proof bar.
| # | Tool | Customers | Proof |
|---|---|---|---|
| 1 |  Regal | 40 | |
| 2 |  Retell AI | 32 | |
| 3 |  Hippocratic AI | 28 | |
| 4 |  Assort Health | 24 | |
| 5 |  Bland AI | 21 | |
| 6 |  PolyAI | 18 | |
| 7 |  Replicant | 15 | |
| 8 |  Synthflow | 14 | |
| 9 |  Arini | 11 | |
| 10 |  Vapi | 10 | |
| 11 |  Goodcall | 3 |
3 companies run two of these tools or more. The most common pair is Bland AI with Regal, at 1 company.
Regal40 customersRegal is used by 40 companies on usedby, 26 confirmed by a case study, a named quote or a press release. Named customers include Toyota, Coursera, and Mutual of Omaha. Who uses Regal, Regal vs Retell AI
Customer page: regal.ai. Latest check of 40 of 40 lines: Oct 8, 2026.
Retell AI32 customersRetell AI is used by 32 companies on usedby, 14 confirmed by a case study, a named quote or a press release. Named customers include Grab, Lenovo, and Motorola. Who uses Retell AI, Regal vs Retell AI
Customer page: retellai.com. Latest check of 32 of 32 lines: Oct 5, 2026.
Hippocratic AI28 customersHippocratic AI is used by 28 companies on usedby, 9 confirmed by a case study, a named quote or a press release. Named customers include Belong Health, Burjeel Holdings, and Cincinnati Children's. Who uses Hippocratic AI, Hippocratic AI vs Regal
Customer page: hippocraticai.com. Latest check of 28 of 28 lines: Oct 7, 2026.
Assort Health24 customersAssort Health is used by 24 companies on usedby, 12 confirmed by a case study, a named quote or a press release. Named customers include Annapolis Internal Medicine, Barrington Orthopedic Specialists, and Catalyst Medical Group. Who uses Assort Health, Assort Health vs Regal
Customer page: assorthealth.com. Latest check of 24 of 24 lines: Oct 8, 2026.
Companies first listed by a tool of this category in the last 90 days.
Side-by-side pages with the companies behind each tool.
Answers drawn from usedby data.
Regal, used by 40 of the 213 companies on usedby in this category. Then come Retell AI (32) and Hippocratic AI (28). Who uses Regal.
Regal: 40 companies on usedby, against 32 for Retell AI. 1 company uses both, counting confirmed and observed lines only.
Yes: 3 of the 213 companies on usedby in this category run two or more. The most common pair is Bland AI with Regal (1 company).
By the number of companies with a public line for each tool, read from dated captures of vendor customer pages, case studies, press releases and job posts. Job-post signals count in the totals and are shown apart. usedby lists a company when a public page shows it, so these counts describe the companies on usedby, not the whole market.