Bolna vs Retell AI

Bolna

Bolna competes on two things Western voice-agent platforms handle badly: Indian language coverage and per-minute price. Being able to swap the recognition, language and speech models independently is genuinely useful when one vendor's accent handling fails on your callers. It is a developer product first — the playground exists, but the APIs and telephony wiring are where the work is.

Pros

• +Over ten Indian languages plus English, an area most voice platforms cover poorly
• +Twenty-plus interchangeable ASR, LLM and TTS models rather than a single fixed stack
• +APIs for agents, calls, numbers, knowledge bases and batch dialling, plus n8n, Make and Zapier
• +6 cents a minute billed in 30-second increments, with volume rates down to about 4.5 cents

Cons

• −Purely metered, so a bad prompt loop turns directly into spend
• −Telephony charges from Twilio, Plivo or Vobiz are additional and not included in the quoted rate
• −Pay-as-you-go requires a credit purchase of at least $10 up front
• −Concurrency and support levels are tied to the Pilots or Enterprise commitments

Retell AI

One of the more honest voice-agent stacks: the pricing page breaks out infrastructure, TTS and LLM cost per minute so you can predict a call's cost instead of guessing. Telephony choice is wide and the concurrency allowance is generous. The catch is that per-minute billing plus add-ons makes a busy contact centre expensive fast, and the cheap end of the range only holds if you pick the cheap models.

Pros

• +Per-minute cost broken down by voice infrastructure, TTS provider and LLM on the public pricing page
• +Telephony via SIP trunking, Twilio and Vonage plus n8n, HubSpot, Make and Go High Level integrations
• +20 concurrent calls included before any concurrency charge
• +Voice, chat and SMS agents share one platform and API
• +HIPAA path exists via a signed BAA covered in the terms of service

Cons

• −Cost per minute more than quadruples between the cheapest and most capable model combinations
• −Knowledge base, denoising, PII removal and branded caller ID are all metered extras
• −No flat-rate plan, so a spike in call volume lands straight on the invoice

Is Bolna cheaper than Retell AI?

On published entry prices, Bolna starts lower — $0.06/min against $0.07/min for Retell AI. Entry price is the lowest paid plan as we last verified it; what each plan includes differs.

Does Bolna or Retell AI have a free tier?

Retell AI has a free tier; Bolna has paid plans only.

Which has a public API, Bolna or Retell AI?

Both ship a public API, so either can be built on; the fact table above shows the platforms each one runs on.