Retell AI vs Synthflow
as AI assistants see them, week of 2026-09-21
Retell AI clearly leads Synthflow in how AI assistants talk about voice agents. Retell AI scores 52 overall (68 ChatGPT, 46 Claude, 48 Perplexity) and gets named in 44 of 60 answers, including a clean sweep on questions like "best AI voice agents in 2026," "best AI receptionist," and "best for booking appointments." Synthflow trails with a 22 overall score and 24 of 60 answers, though it does match Retell AI with 3 of 3 on "best AI voice agent platforms" and "best no-code tool to build a voice AI agent." Head-to-head, Retell AI was named more often in 14 questions versus Synthflow's 1, with 5 ties.
Head to head
| metric | Retell AI | Synthflow |
|---|---|---|
| score | 52 | 22 |
| questions won | 17 | 12 |
By assistant
Retell AI
| assistant | score | named in, this week | usual spot, this week |
|---|---|---|---|
| ChatGPT | 68 | 75% of answers | #1.7 |
| Claude | 46 | 80% of answers | #6.0 |
| Gemini | not sampled this week | ||
| Perplexity | 48 | 65% of answers | #3.4 |
Synthflow
| assistant | score | named in, this week | usual spot, this week |
|---|---|---|---|
| ChatGPT | 35 | 50% of answers | #3.8 |
| Claude | 27 | 60% of answers | #9.3 |
| Gemini | not sampled this week | ||
| Perplexity | 9 | 10% of answers | #2.0 |
Where they differ
Only Retell AI gets named for
- What's the best AI voice agent for inbound customer support calls?
- Which voice AI platform is best for developers?
- What's the best AI voice agent for languages other than English?
- Which AI voice agent has the lowest latency?
- Which voice AI platform sounds the most natural?
Only Synthflow gets named for
nothing exclusive
More comparisons
- Retell AI vs Vapi
- Bland vs Retell AI
- ElevenLabs Agents vs Retell AI
- PolyAI vs Retell AI
- ElevenLabs Agents vs Synthflow
- Bland vs Synthflow
Not sold on either?
Scores count how often each assistant names a product, weighted by position. How the score works · Full AI voice agents leaderboard