Short answer: Pick SuperU if you want the lowest effective cost per minute and a fast, no code rollout. Vapi is capable, but the real world minute cost usually rises once you add separate STT, TTS, LLM and telephony bills. Vapi’s enterprise options are strong, yet you pay for that stack control.
Snapshot scorecard
| Dimension | SuperU AI | Vapi |
|---|---|---|
| Cost | SuperU offers $0.02 per minute for large volume contracts. | $0.14 per minute = platform fee + separate STT, TTS, LLM and telephony costs. |
| Latency | SuperU markets sub-300 ms live voice translation. Uses modern low latency components in practice. | Public claims include sub-500 ms interactions. |
| Ease of use | No code studio and templates for inbound and outbound. Fast test calls. | Developer first build with bring your own providers. Excellent if you want to wire components. |
| Scalability | Designed for automated inbound and high volume outbound without you owning telephony complexity. | Unlimited concurrency on Enterprise with reserved capacity. |
| Adoptability | 100+ languages live voice features and ready made templates. Free to start. | Broad language and voice choice via providers like ElevenLabs and Deepgram. |
Cost math you can verify
Vapi’s fee is only the starting line. Vapi charges $0.05 per minute for platform usage, then you also pay your STT, TTS, LLM and telephony vendors. Their own pages and community threads confirm the $0.05 platform fee, and third party explainers show why the effective minute price rises once you add providers.
SuperU compresses the all-in minute. SuperU built the world’s affordable voice stack with $0.02 per minute at large volume. Treat $0.02 as a sales negotiated high volume tier.
Illustrative monthly totals
- 50,000 minutes
- SuperU At $0.02 (volume) → $1,000.
- Vapi at ~$0.14 effective → $7,000.
You feel the gap most in outbound campaigns and 24×7 inbound support.
Latency and call flow responsiveness
For natural phone conversations you want round trip under a second. Industry guidance says one way voice latency under 150–300 ms feels fine.
What the building blocks can do today
- STT. AssemblyAI’s streaming API reports ~300 ms P50. Deepgram markets sub-300 ms real time latency.
- TTS. ElevenLabs Flash models target ~75 ms audio start for real time.
What platforms claim
- SuperU offers 300 ms latency. That bodes well for turn taking when paired with a fast STT and TTS.
- Vapi advertises sub-500 ms. Community and reviewer write ups often observe ~550–800 ms end to end depending on model load and geography.
Bottom line for latency Both can land under a second. SuperU leans into pre tuned defaults and no code flow so you get that outcome without juggling providers. With Vapi, you can tune deeply, but you own more of the tuning.
Ease of use for non dev teams
- SuperU gives you a studio, test calls, and templates so non dev teams can ship in hours, not sprints. you can deploy voice campaigns in minutes, and flows for inbound and outbound.
- Vapi is developer first. It is an excellent API platform if you want to bring specific STT, LLM and TTS and wire everything. That is power with extra responsibility.
Scalability and burst handling
- SuperU: Built to handle a million call capacity, 100 concurrent conversations, and 100+ languages coverage. That gives you space to grow without re-architecting.
- Vapi Enterprise provides a request for the number of concurrency lines and reserved capacity. This is useful if you plan to have a very high number of concurrent sessions.
Adoptability languages, accents, templates, credits
Languages and accents
- SuperU lists 50 plus languages and dialects for live voice with latency under 300 ms
- Vapi taps the catalogs of providers like ElevenLabs and Deepgram, so you can choose voices and models per use case.
Templates
- SuperU ships ready inbound and outbound templates so you start from a working call, not a blank file.
- Vapi offers examples and deep provider integrations, aimed at engineering teams.
Scenario totals you can show finance
Assumptions
Vapi platform $0.05 per minute plus typical provider add ons that many teams report. SuperU at $0.05 public usage with a $0.02 volume tier available by quote. Sources provided
| Monthly minutes | SuperU volume at $0.02 | Vapi effective at ~$0.14 |
|---|---|---|
| 10,000 | $200 | $1,400 |
| 50,000 | $1,000 | $7,000 |
These deltas are why SuperU wins total cost of ownership for teams that actually place calls at scale.
Verdict and who should pick what
Choose SuperU if you want the cheapest at scale, easy rollout, and predictable minute math. You start with $0.02 per minute available for large volumes by quote. You also get templates and quick testing, so non dev teams can launch without writing glue code
Choose Vapi if your priority is deep platform control, strict enterprise paperwork, or you need to pick specific STT or TTS vendors for niche reasons. Budget for the platform fee plus provider bills.
FAQ
1. Is SuperU really the cheapest at scale?
Yes, for practical, at scale calling. You can unlock $0.02 per minute at large volume via sales. Vapi’s $0.05 platform fee is only part of the true per minute.
2. How fast are responses?
Modern stacks can land under a second end to end. SuperU cites sub-300 ms for live voice translation. Vapi markets sub-500 ms. Under the hood, STT at ~300 ms P50 and TTS at ~75 ms make that feasible. Network and model choice still matter.
