Retell AIAI Voice Agents That Automate Phone Calls
vs
SimThe open-source AI workspace to build, distribute, and govern AI agents
Comparison · AI Agents · weekly run Nov 3
Retell AI vs Sim
Which one do AI engines recommend, and how do they differ on price, fit and features?
The short answer
Sim is the stronger AI pick in AI Agents: it has a visibility score of 2.3 versus 2 for Retell AI.
Choose Retell AI if…
- You need HIPAA coverage
- You prefer a larger, established vendor (51–200 employees)
- Usage-based pricing suits your budget better than per seat
- Highly rated by developers and SMBs
Choose Sim if…
- You want the brand AI engines rank higher (2.3 vs 2)
- Per seat pricing suits your budget better than usage-based
- Technical control and model flexibility
- Self-hosting option
AI visibility side by side
Latest weekly run · Nov 3
| Metric | Retell AI | Sim |
|---|---|---|
| Visibility score | 2% | 2.3% |
| Change vs last week | New | New |
| Rank in AI Agents | #42 | #39 |
| Share of voice | 0.5% | 0.7% |
| Mentions this run | 3 | 5 |
| Positive in AI answers | — | — |
The stronger value in each row is marked with a ✓.
Visibility score trend
Weekly runs over the last 60 days
Retell AI 0pp · Sim 0pp over 0 weekly runs.
Engine by engine
Sim leads on 1 of 3 engines
ChatGPT
AI Mode
Perplexity
Retell AISim
Head to head in AI answers
0 engine answers name both brands
0Retell AI ranked higher
0Sim ranked higher
Features, pricing & fit
| Dimension | Retell AI | Sim |
|---|---|---|
| Pricing model | Usage-based | Per seat |
| Entry price | Contact sales | Free; paid from $25 per seat / mo |
| Free plan | Yes | Yes |
| Deployment | Cloud platform, with enterprise on-premises deployment available | Cloud-hosted, or self-hosted in your own cloud with Docker or Kubernetes |
| Integrations | — | 275+ |
| Compliance | HIPAA, SOC 2 Type II, GDPR, ISO 27001 | SOC 2 Type II, ISO 27001, GDPR |
| Support | Community and email support, 24/7 omnichannel support with dedicated portal (Enterprise), Dedicated implementation support (Enterprise), Named account manager (Enterprise) | Dedicated support on the Enterprise plan |
| Founded | 2023 | 2025 |
| Headquarters | Redwood City, California | San Francisco, CA, United States |
| Employees | 51–200 | 11–50 |
| Funding | Seed · $5M raised | Series A · $7M raised |
| Best for | Businesses that run high call volumes in healthcare, insurance, financial services, logistics and similar fields, and teams that want to build and change voice agents themselves. | Companies that need to build, deploy, and govern AI agents across the organization with central control over access, spend, and data |
Plans side by side
Retell AI
Pay as you go$0per minute, $0.07-$0.31 for voice agents
EnterpriseCustomcustom pricing
Sim
Free$0free forever
Pro$25per user/month, billed monthly
Max$100per user/month, billed monthly
EnterpriseCustomcustom, talk to sales
Pros and cons
Themes from the AI answers that mention each brand
Retell AI
- Highly rated by developers and SMBs
- One of the highest customer star ratings
Sim
- Technical control and model flexibility
- Self-hosting option
Data collected ·ChatGPT, Perplexity, Google AI Mode·coverage 100%·next run
Cite as: SlateIndex, “Retell AI vs Sim”, https://slateindex.ai/compare/retell-ai-vs-sim, data of Nov 3, 2026. Licence: CC BY 4.0.