Cozzo-tested · Oct 20, 2026
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Vapi vs Retell vs Bland: tested on real phone calls
On our real phone calls, Retell AI replied fastest (1.04 s median), Vapi came next (1.56 s) and Bland AI was slowest (1.86 s). Vapi cost the least per minute on our calls (about $0.08–0.09/min).
The short answer
- Fastest: Retell AI, 1.04 s median reply time (tied 1 of 8 platforms we tested).
- Cheapest on our calls: Vapi, about $0.08–0.09/min, with you picking (and paying for) each model.
- Simplest bill: Bland AI, one talk-time rate with the LLM, transcription and voice included.
- Fewest transcription errors: Retell AI (0.0%); the most: Bland AI (8.2%).
- Gap from fastest to slowest: 0.82 s per reply, which a caller can hear.
Speed and accuracy on real phone calls
Ordered by median reply time. 33 calls and 100 timed turns in all.
Retell AI
- Median reply time, phone
- 1.04 s
- 90th percentile (p90), phone
- 1.22 s
- Place among 8 platforms
- tied 1 of 8
- Phone calls / turns timed
- 11 / 33
- Talk-over (replies started while the caller spoke)
- 0
- Transcription error rate (WER)
- 0.0%
- Median reply time, browser connection
- 0.76 s
- Setup tested (vendor defaults)
- gpt-4.1-mini, ElevenLabs “Adrian” voice (Retell defaults)
Vapi
- Median reply time, phone
- 1.56 s
- 90th percentile (p90), phone
- 1.83 s
- Place among 8 platforms
- 7 of 8
- Phone calls / turns timed
- 11 / 34
- Talk-over (replies started while the caller spoke)
- 0
- Transcription error rate (WER)
- 2.2%
- Median reply time, browser connection
- 1.15 s
- Setup tested (vendor defaults)
- gpt-4o-mini, Deepgram nova-3, Vapi “Elliot” voice (Vapi defaults)
Bland AI
- Median reply time, phone
- 1.86 s
- 90th percentile (p90), phone
- 2.02 s
- Place among 8 platforms
- 8 of 8
- Phone calls / turns timed
- 11 / 33
- Talk-over (replies started while the caller spoke)
- 0
- Transcription error rate (WER)
- 8.2%
- Median reply time, browser connection
- Not tested
- Setup tested (vendor defaults)
- Bland default model and voice
Reply time is the gap from the end of the caller’s speech to the agent’s first reply audio, timed from our recording of real phone calls (Twilio calling each vendor from a US number, Ashburn, Virginia (US East)), on each vendor’s default model and voice, with the same short dental-receptionist script. Bland had no inbound number on our plan, so it dialed our Twilio number instead. Small samples: differences of a few hundredths of a second are noise. Ranking order comes only from the measured medians.
Cost: list prices and what our calls cost
List prices from each vendor’s pricing page, re-checked Oct 21, 2026. Itemized ranges and 1,000-minute totals come from our pricing guides.
Retell AI
- How you’re billed
- $0.055/min voice infrastructure, plus the voice, LLM and phone line you pick
- List price (vendor’s pricing page)
- $0 platform fee; $0.07–$0.31/min for voice agents
- Per minute, itemized (our pricing guide)
- 13.4¢–33¢
- 1,000 minutes a month at list price
- $134–$330
- Phone line
- $0–$0.015/min
- Measured cost on our calls
- $0.080–0.084 per ~32 s call (about $0.15/min)
- Free to start
- $10 in free credits, no platform fee
- Concurrent calls
- 20 included; extra $8 per concurrent call a month
- HIPAA
- BAA you can self-sign (Retell’s compliance docs); no separate HIPAA fee listed
Vapi
- How you’re billed
- $0.05/min Vapi hosting, plus the transcriber, model and voice you pick at cost
- List price (vendor’s pricing page)
- $0 to start; $0.05/min Vapi hosting, models billed pass-through at cost
- Per minute, itemized (our pricing guide)
- 8.2¢–12.9¢
- 1,000 minutes a month at list price
- $82–$129
- Phone line
- $0 on Vapi’s own lines
- Measured cost on our calls
- $0.042–0.051 per ~32 s call (about $0.08–0.09/min)
- Free to start
- $5 in free credits, 4 concurrent calls
- Concurrent calls
- 4 included (10 on Core at $29/mo, 30 on Pro); extra lines $10/mo
- HIPAA
- HIPAA add-on: $2,000/mo (DPA + BAA)
Bland AI
- How you’re billed
- One talk-time rate that includes the LLM, transcription and voice: $0.14/min Start, $0.12/min Build
- List price (vendor’s pricing page)
- $0.14/min, $0 platform fee
- Per minute, itemized (our pricing guide)
- 12¢–14¢
- 1,000 minutes a month at list price
- $140 on Start
- Phone line
- Ask Bland
- Measured cost on our calls
- about $0.068 per ~29 s call (about $0.14/min)
- Free to start
- 2 credits plus an inbound number, no card required
- Concurrent calls
- 10 on Start, 50 on Build ($299/mo)
- HIPAA
- HIPAA with a signed BAA (Bland’s pricing FAQ); BAA listed under Enterprise
Measured cost is what our ~30-second test calls cost on each vendor’s own billing, on default settings; it is not a list price. Vapi’s 1,000-minute range uses its own calculator mix (Deepgram, OpenAI, ElevenLabs); Retell’s uses its four recommended LLMs and its voice range. Twilio added about $0.01/min for the phone leg (SIP dial-out plus recording).
Who each one is best for
Pick Retell AI if…
You want the fastest replies of the three and clean transcription (1.04 s median, 0.0% WER on our calls), a no-code flow builder plus an API, 20 concurrent calls included and a BAA you can sign yourself. Watch the LLM and voice you pick: they move the per-minute price the most.
Vendor fit: Teams that want a no-code flow builder plus an API with itemized per-minute pricing.
Pick Vapi if…
You’re a developer who wants to pick every part of the stack (model, transcriber, voice, carrier) and pay those providers at cost. It was the cheapest of the three on our calls (about $0.08–0.09/min), but on default settings it was slower than Retell (1.56 s). HIPAA is a $2,000/mo add-on.
Vendor fit: Developers who want to choose their own LLM, transcriber, voice and telephony provider.
Cozzo may earn a commission if you sign up through some links. It never affects our rankings or test results. Disclosure
Pick Bland AI if…
You want one flat per-minute price with no model pass-through bills, and you can live with slower replies on default settings (1.86 s median and 8.2% WER on our calls, the weakest of the three). Bland’s pricing page says phone-line charges are billed separately, so ask for that rate.
Vendor fit: Teams that want one flat per-minute price with no model pass-through bills.
Cozzo tip: I tested all three on their default settings. Before you choose, put your own script through each free tier and listen to a few calls back. A tenth of a second you can measure; awkward pauses you can hear.
Vapi vs Retell vs Bland: FAQ
Which is fastest: Vapi, Retell or Bland?
Retell AI, on Cozzo’s real phone calls: Retell AI 1.04 s, Vapi 1.56 s, Bland AI 1.86 s median reply time (end of the caller’s speech to the agent’s first reply audio), on each vendor’s default model and voice. Retell AI placed tied 1 of 8 platforms we tested; Bland AI placed 8 of 8. These are small samples (11, 11, 11 calls), so read them as defaults, not a promise for your setup.
Which is cheapest?
On our own test calls, Vapi cost the least: Retell AI about $0.15/min, Vapi about $0.08–0.09/min, Bland AI about $0.14/min. At list prices for 1,000 minutes a month, our pricing guides come to Retell AI $134–$330, Vapi $82–$129, Bland AI $140 on Start. Vapi and Retell depend on the model and voice you pick; Bland is one rate, with phone charges billed separately.
Which has the simplest pricing?
Bland AI. One talk-time rate that includes the LLM, transcription and voice: $0.14/min Start, $0.12/min Build. Vapi and Retell bill a platform fee per minute plus each model, voice and phone provider, so their totals move with your choices.
Which is best for HIPAA or healthcare calls?
All three offer a BAA, on different terms. Retell AI: BAA you can self-sign (Retell’s compliance docs); no separate HIPAA fee listed. Vapi: HIPAA add-on: $2,000/mo (DPA + BAA). Bland AI: HIPAA with a signed BAA (Bland’s pricing FAQ); BAA listed under Enterprise. Ask for the BAA before any patient call goes through the agent.
How did Cozzo test them?
Twilio called each platform from a US number (Ashburn, Virginia (US East)) on Oct 20, 2026 with the same scripted dental-receptionist call, on each vendor’s default model and voice. We timed 100 turns across 33 calls from the call recordings, not vendor dashboards. Twilio added about $0.01/min for the phone leg (SIP dial-out plus recording).
Do affiliate links change these results?
No. Cozzo may earn a commission if you sign up for Vapi through our link. The order on this page comes only from the measured median reply time, and no vendor paid for, reviewed or approved these results.
Go deeper
- Vapi vs Retell AI: tested on real phone calls
- Vapi vs Bland AI: tested on real phone calls
- Retell AI vs Bland AI: tested on real phone calls
- Vapi vs Retell AI: pricing and features side by side, with a cost-at-volume calculator
- Vapi vs Bland AI: pricing and features side by side, with a cost-at-volume calculator
- Retell AI vs Bland AI: pricing and features side by side, with a cost-at-volume calculator
- Retell AI Pricing Explained
- Vapi Pricing Explained
- Bland AI Pricing Explained
- Retell AI Alternatives Compared
- Vapi Alternatives Compared
- Bland AI Alternatives Compared
- Full phone-call benchmark: all 8 platforms, method and limits. All Cozzo benchmarks.
- Methodology and how we test.
Cozzo may earn a commission if you sign up through some links. It never affects our rankings or test results. Read our disclosure.