Relay.app vs Vapi
Relay.app and Vapi are both AI Platforms tools in our directory. This side-by-side comparison covers pricing, user ratings, supported platforms, key features and open-source status so you can decide which one fits your needs.
Side-by-side comparison
| Attribute | Relay.app | Vapi |
|---|---|---|
| Vendor | Relay.app | Vapi |
| Rating | ★ 4.6 | ★ 4.5 |
| Pricing | Freemium | Pay-as-you-go |
| Platforms | Web | API |
| Key features | Human approvals, AI steps, Pretty flows | Sub-second voice agent loop, BYO models (STT/LLM/TTS) or defaults, Phone numbers, transfers & IVR flows |
| Headquarters | San Francisco, USA | San Francisco, USA |
| Founded | 2023 | 2023 |
| Open source | No | No |
Key differences
- Relay.app has a higher user rating (4.6★ vs 4.5★).
- Relay.app is Freemium, while Vapi is Pay-as-you-go.
- Relay.app runs on Web; Vapi runs on API.
Frequently asked questions
Is Relay.app or Vapi better?
By user rating, Relay.app scores higher (4.6★ vs 4.5★). Both are capable AI Platforms tools, so review the feature comparison for your use case.
Which is cheaper, Relay.app or Vapi?
Relay.app is Freemium and Vapi is Pay-as-you-go. Check each product page for current plan details.
Are Relay.app and Vapi open source?
No — neither Relay.app nor Vapi is open source.