Retell AI vs Synthflow:Which is more popular by branded search?
In August 2026, Retell AI had more branded searches than Synthflow among AI voice agents worldwide. Retell AI was estimated to have 74K branded searches compared to Synthflow’s 5.4K, and held a 65.1% Share of Search versus Synthflow’s 4.7%. These are worldwide searches for English-language branded terms.
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Which is more popular in search, Retell AI or Synthflow?
Compare the platforms used to build AI voice agents. Branded searches tell you how often people look for a brand by name or related terms. Comparing these searches across competitors helps you see how popular each brand is over time.
Share of Search by month for Retell AI, Synthflow. The figures are in the table below the chart.
View monthly share of search table
| Month | Retell AI | Vapi | Bland AI | Synthflow |
|---|---|---|---|---|
| Oct 2025 | 54.1% | 24.2% | 10.8% | 10.8% |
| Nov 2025 | 55.2% | 24.7% | 11% | 9% |
| Dec 2025 | 60.1% | 22% | 9.8% | 8% |
| Jan 2026 | 58.8% | 21.5% | 11.8% | 7.9% |
| Feb 2026 | 58.1% | 21.3% | 14.2% | 6.4% |
| Mar 2026 | 54.8% | 24.5% | 13.4% | 7.3% |
| Apr 2026 | 56.9% | 25.5% | 11.4% | 6.2% |
| May 2026 | 53.9% | 29.5% | 10.8% | 5.9% |
| Jun 2026 | 55.5% | 24.9% | 13.6% | 6.1% |
| Jul 2026 | 55.5% | 24.9% | 13.6% | 6.1% |
| Aug 2026 | 65.1% | 19.5% | 10.6% | 4.7% |
| Sep 2026 | — | — | — | — |
How has the Retell AI and Synthflow comparison changed over the last 12 months?
3 findings
- Retell AI was ahead of Synthflow in every measured month of the 11 months ending August 2026.
- Across the 11 months ending August 2026, Retell AI’s estimated Share of Search among AI voice agents worldwide moved from 54.1% to 65.1%, and its estimated monthly branded searches moved from 60.5K to 74K.
- Across the 11 months ending August 2026, Synthflow’s estimated Share of Search among AI voice agents worldwide moved from 10.8% to 4.7%, and its estimated monthly branded searches moved from 12.1K to 5.4K.
How did search popularity change for AI voice agents worldwide in August 2026?
2 changes
In August 2026, Retell AI gained estimated Share of Search among AI voice agents worldwide, from 55.5% to 65.1%.
In August 2026, Synthflow lost estimated Share of Search among AI voice agents worldwide, from 6.1% to 4.7%.
How each brand is measured
Brandwave collects information about searches that people make online using Retell AI’s and Synthflow’s names. When viewed over time, estimated search volumes for these branded terms can be used to understand whether interest in the brands is growing, holding steady, or fading.
Put your own brand in this comparison
Brandwave tracks your branded demand next to the rival you actually watch, with your campaigns, spend and outcomes on the same timeline.