Retell AI vs Synthflow
In short, Retell AI leads on voice and phone (8.4 to 7.5). Here's who should pick which.
Published · Updated . Facts checked November 12, 2026. Some links on this page are affiliate links; see our disclosure.
Which is better, Retell AI or Synthflow?
It depends on your size and the job. By size, neither is built for small businesses; Retell AI fits mid-size companies and enterprises better. By job, Retell AI leads on voice and phone. Choose Retell AI if you have someone who can build a custom voice agent and want high call quality at transparent per-minute prices. Choose Synthflow if you want no-code voice agents with an enterprise contract, support and security review.
Choose Retell AI if you have someone who can build a custom voice agent and want high call quality at transparent per-minute prices.
Visit Retell AIChoose Synthflow if you want no-code voice agents with an enterprise contract, support and security review.
Visit SynthflowFit by business size
| Measure | Retell AI | Synthflow |
|---|---|---|
| Small business (1 to 50 people) | Not built for it | Not built for it |
| Mid-size company (50 to 1,000 people) | 7.2 | 7.0 |
| Enterprise (1,000+ people) | 7.4 | 7.2 |
Scores by job
| Measure | Retell AI | Synthflow |
|---|---|---|
| Voice and phone | 8.4 | 7.5 |
Base scores
| Measure | Retell AI | Synthflow |
|---|---|---|
| Does the work | 8.0 | 7.5 |
| Reach | 6.0 | 6.0 |
| Setup | 5.5 | 6.0 |
| Control | 8.0 | 7.5 |
| Value | 8.0 | 5.0 |
| Trust | 7.5 | 7.0 |
| Enterprise readiness | 7.5 | 8.0 |
Which jobs each takes on
| Job | Retell AI | Synthflow |
|---|---|---|
| Answers customers | ||
| Finds and follows up with leads | ||
| Writes and posts marketing | ||
| Handles email and calendar | ||
| Takes and makes phone calls | ||
| Back office: reports, docs, data | ||
| Runs on a schedule or trigger | ||
| Asks before risky actions | ||
| Connects to hundreds of apps | ||
| API or MCP access |
Price and fine print
Prices and terms as of November 2026, from each company's own site.
| Detail | Retell AI | Synthflow |
|---|---|---|
| Type | Voice agent | Voice agent |
| Starting price | No monthly fee plus about $0.07 to $0.31 per minute | Custom pricing |
| Free plan | $10 in free credits | No free plan or trial |
| Extra charges | Extra concurrency $8 per line per month; numbers $2 per month | Annual enterprise agreement only |
| Refunds | Not stated | Not stated |
| Best for | Teams building custom voice agents for inbound or outbound calls. | Mid-size and large teams that want no-code voice agents under contract. |
Retell AI
- Excellent call quality
- Transparent per-minute pricing
- Choice of models and voices
- Free credits to start
- You build the agent yourself
- Costs add up across components
- Voice only
- Some pricing page inconsistencies
Synthflow
- No-code voice building
- Enterprise support and security review
- Inbound and outbound
- Telephony included in contracts
- Annual contracts only
- No trial
- No public pricing
- Voice only
Retell AI vs Synthflow: questions
Is Retell AI better than Synthflow?
It depends on the job. In short, Retell AI leads on voice and phone (8.4 to 7.5). Choose Retell AI if you have someone who can build a custom voice agent and want high call quality at transparent per-minute prices. Choose Synthflow if you want no-code voice agents with an enterprise contract, support and security review.
Which is built for my company's size?
Retell AI is built for: mid-size company, enterprise. Synthflow is built for: mid-size company, enterprise.
Which costs less, Retell AI or Synthflow?
Retell AI: no monthly fee plus about $0.07 to $0.31 per minute, as of November 2026. Synthflow: custom pricing, as of November 2026. Check extra charges too: Retell AI, extra concurrency $8 per line per month; numbers $2 per month; Synthflow, annual enterprise agreement only.