Bolna vs Vapi vs Retell for Indian businesses (2026): pricing, Hindi support, telephony
Short answer: As of 14 October 2026, Bolna lists 6.00 cents (Rs 5.52) a minute pay-as-you-go, falling to about 4.5 cents on larger top-ups and about 4.2 cents on a $500 pilot pack, with Indian numbers from Plivo or Vobiz at $5 a month and documented 140 and 160-series provisioning. Vapi charges a $0.05 a minute hosting fee with speech and language models passed through at cost (its own calculator puts 1,000 minutes at $82 to $129), sells only free US inbound numbers and expects you to bring a carrier for India. Retell charges $0.055 a minute for its voice engine plus $0.015 a minute for standard voices and a per-minute model charge, sells US and Canada numbers only, and connects India through your own SIP trunk. Bolna is the only one of the three whose pages mention DLT, 140 or 160 series, Hindi-specific transcription models or Indian data residency. None of the three publishes a latency figure on the pages we read.
Every number below is quoted from the vendor's own pricing or documentation page, with facts checked on 14 October 2026 and URLs under Sources. Prices change often; re-check before you commit. We are not a reseller for any of the three; we build custom voice agents on whichever fits the job (second-last section).
Per-minute pricing, as each vendor states it
| Bolna | Vapi | Retell | |
|---|---|---|---|
| Platform charge | 6.00¢ (Rs 5.52) per minute pay-as-you-go, bundled; "about 4.5¢ (Rs 4.15)" on larger top-ups | $0.05 per minute "Vapi hosting", pre-paid | $0.055 per minute "Retell Voice Infra" |
| Speech and language models | Included in the bundled rate; bring your own keys for LLM, TTS and ASR if you prefer | "Models pass-through at cost": Deepgram $0.0095 to $0.0099, OpenAI $0.0077 to $0.0452, ElevenLabs $0.0146 to $0.0238 per minute in Vapi's calculator | TTS $0.015 (Retell, Cartesia, OpenAI, Minimax, Fish, Inworld voices) or $0.04 to $0.10 (ElevenLabs tiers); LLM from $0.0016 (GPT 5 nano) to $0.64 (fast-tier GPT 6 Astra) per minute |
| Vendor's own all-in example | Not published beyond the bundled rate; FAQ says telephony and platform fee are added per minute without amounts | $82 to $129 a month for 1,000 minutes | Not published as a single figure |
| Prepaid packs | Pilot: $500 for 12,000 minutes (about 4.2¢) or $300 for 6,500 minutes (about 4.6¢), one month of dedicated support, 25 concurrent calls | Core $29 a month; Pro 10% of hosting fee with a $999 a month minimum; Premier custom | None listed; enterprise custom |
| Free credit | $5 on sign-up | $5 on the free tier | $10 |
| Concurrency | 25 on Pilot; enterprise custom | 4 on free, 10 on Core, 30 on Pro; $10 per extra line a month | First 20 free, then $8 per concurrency a month |
Three cautions: Bolna's rate is bundled, so add a transcriber, model and voice to the other two before comparing; Vapi's example excludes telephony; and Retell's model prices span more than a hundredfold, so the model you choose, not the platform fee, decides the bill.
Indian telephony and numbers
Bolna. Its number guide sells numbers in "United States and India": US through Twilio, Indian through Plivo or Vobiz, at $5 a month each with call charges separate. "Indian numbers require compliance approval. You may need to submit identity documents before your number is activated." Its regulated-number guide documents the 140 series (promotional, via Vobiz, after Principal Entity registration on the Tata Teleservices DLT portal and a Rs 5,900 payment) and the 160 series (service and transactional, via Plivo, active only after header and template approval). Exotel is a bring-your-own option for inbound and outbound in India on your own ExoPhones. Indian-server routing, for calls processed on Indian infrastructure, works with Plivo only ("Twilio is not supported for Indian server routing"), and bringing your own model keys routes calls through US servers.
Vapi. "Free Vapi numbers use US area codes, and only inbound calls are supported." For outbound or any other country you import a number from Twilio, Telnyx, DIDWW or Vonage, or connect a SIP trunk. Telephony is billed by the carrier: Twilio $0.008 a minute inbound and $0.014 outbound, Vonage $0.00814, Telnyx $0.0055, with Vapi's own SIP, WebSockets and WebRTC free. India, DLT and the 140 and 160 series do not appear on the pages we read.
Retell. "Currently we only support purchase of US and Canada numbers", at $2 a month on Twilio or Telnyx ($5 for US toll-free), with calls to 15 countries. For India the route is custom telephony: an elastic SIP trunk from Twilio, Vonage, Telnyx or another provider pointed at sip.retellai.com, or an imported number. Telephony is $0.015 a minute for listed countries and "No Charge for Sip Trunking/Custom Telephony". India-specific compliance is not mentioned on the pages we read; the 140 or 160 number is your job with an Indian operator, and Retell carries the call.
Hindi and Indian-language speech
Bolna states on its pricing page that it supports "10+ vernacular Indian languages including Hinglish, Hindi, Tamil, Telugu". Its Indian-server documentation names the engines: transcription from Deepgram (nova-2 or nova-3 with language hi, multi-hi or en-IN), Azure, Sarvam, ElevenLabs or Smallest; synthesis from ElevenLabs, Sarvam, Azure TTS or Cartesia; Azure OpenAI as the model on that path. Sarvam, the India-built speech provider, on both lists is the most concrete Indian-language signal among the three.
Vapi is provider-agnostic. Its multilingual guide lists Deepgram, Google, Gladia, AssemblyAI, Azure, OpenAI Whisper and Speechmatics as transcribers, with auto-detection on the first four, and points you to each provider's language list. Its own voices list Hindi (code hi) among 30-plus languages in version 1; version 2 "supports 40+ languages and defaults to automatic language detection" without naming them. ElevenLabs voices in Vapi list Hindi on Flash v2.5, Multilingual v2 and v3. Hinglish code-switching is not addressed.
Retell has a Hindi landing page ("Talk to Your Customers in Hindi Instantly") under a heading "Built to Support 55+ Languages" that also lists Kannada, Marathi, Tamil and Indian English; a 2025 company blog counts "31+", so the figures disagree. The page names no Hindi speech-to-text or text-to-speech provider, offers no Hindi-specific evidence, and its "industry-leading low latency, high accuracy" claim has no figure. Retell's pricing page does not say which of its $0.015 voices cover Hindi; ElevenLabs Multilingual v2, at $0.06 a minute on Retell, lists Hindi on Vapi's provider page.
Latency
As the vendors state it: Bolna's pricing page makes no latency claim, and its Indian-server guide aims for "the lowest possible latency for calls to Indian phone numbers" without a number. Vapi's pricing page has none; its SLAs cover support response and uptime (99% Pro, 99.9% Premier). Retell's Hindi page says "industry-leading low latency" without a figure. If anyone quotes you milliseconds, ask for the page it came from.
Compliance tooling
| Bolna | Vapi | Retell | |
|---|---|---|---|
| Indian regulation | Documented 140 and 160-series provisioning; DLT registration guidance; compliance@bolna.ai supplies a sample Letter of Authorisation; "Stay compliant with TRAI regulations" guardrails topic | Not mentioned on pages read | Not mentioned on pages read |
| Data residency | Indian-server routing on Plivo so calls are "processed entirely on Indian infrastructure" | Not mentioned on pages read | Not mentioned on pages read |
| Certifications and add-ons | Not mentioned on the pricing page | HIPAA add-on $2,000 a month with a BAA; zero data retention from Core; RBAC on Pro; SSO and custom RBAC on Premier | "SOC 2 certified, HIPAA-ready, with SSO and custom compliance terms"; PII removal $0.01 a minute; safety guardrails $0.005 a minute; AI quality assurance $0.10 a minute after 100 free minutes; branded call $0.10 per outbound call; verified phone number $10 |
| Bring your own keys | Yes, for LLM, TTS and ASR (routes via US servers) | Yes, provider bills you directly | Custom LLM and telephony supported |
Read the first row carefully. Under TRAI's 2025 amendment a promotional AI call must come from a 140-series number by a DLT-registered sender, to a DND-scrubbed list, with the auto-dialler declared to the operator in writing; no platform does that for you, but only Bolna documents the path. Our 140 number series guide walks through every step with the TRAI clauses quoted.
When to pick each
- Pick Bolna when the calls are in India, in Hindi or another Indian language, and you want the platform to handle Indian numbers, the 140 or 160 application and Indian-server routing. The bundled rate simplifies a first pilot budget, and Pilot packs include 25 concurrent calls.
- Pick Vapi when your engineers want to choose every component (seven transcribers, several voice vendors, models at cost) and you will run a Twilio, Telnyx or Vonage account for Indian numbers. Its free tier is the cheapest prototype, and HIPAA is a priced add-on for US healthcare.
- Pick Retell when you want a US-facing stack with SOC 2, per-minute safety and PII add-ons and a wide model menu, and will route Indian calls over your own SIP trunk. Twenty free concurrent calls help with inbound bursts.
- Pick none yet if you cannot name the one call flow the agent will own, the number series it will call from and who it transfers to. The platform is the cheapest line in a voice deployment.
Built on any of them by Digital Patron
We build custom voice agents on Bolna, Vapi or Retell, chosen per project, from $599 for a single flow (one language, one flow such as inbound FAQ, lead qualification or appointment reminders, with transfer to a human) to $6,000+ for multi-flow, CRM-integrated deployments. Build fees are billed in USD; Indian clients are invoiced in INR with GST. Platform usage (minutes, numbers, models, add-ons) is billed to you by the provider at its own rates. We have no published voice case study yet; the AI agent case studies we publish are text and workflow agents, so read them as evidence of how we build, not of voice outcomes. Other published prices are on the pricing page; a free audit is the right first step if you are unsure which flow to automate.
Frequently asked questions
Which is cheapest per minute for an Indian business?
On list prices, Bolna's bundled 6 cents (Rs 5.52) a minute, or about 4.2 to 4.6 cents on a Pilot pack, versus Vapi's $0.05 hosting plus models at cost ($0.082 to $0.129 in its own example) and Retell's $0.055 plus a voice and a model. Only Bolna publishes an Indian number price ($5 a month).
Can I get a 140-series number through Vapi or Retell?
Not from them. Vapi sells only free US inbound numbers and Retell US and Canada numbers; both carry Indian calls over a carrier or SIP trunk you provide. The 140 number comes from an Indian operator or reseller after DLT registration; Bolna documents that path for 140 (Vobiz) and 160 (Plivo).
Which handles Hindi best?
None of the three publishes a Hindi accuracy figure, so we will not rank them. Bolna is the only one whose docs name Hindi-specific transcription settings (Deepgram hi, multi-hi, en-IN) and Sarvam on both the speech-to-text and text-to-speech sides. Vapi supports Hindi through the providers you select; Retell lists Hindi among 55-plus languages without naming engines.
Do any of them keep call data in India?
Bolna documents an Indian-server configuration (Plivo, listed providers, Azure OpenAI) so calls are processed on Indian infrastructure, and notes that bringing your own keys routes calls through US servers. The Vapi and Retell pages we read do not mention Indian data residency.
Do I still need DLT registration if the platform is compliant?
Yes. DLT registration, 140-series numbers, DND scrubbing and the written auto-dialler declaration are the sender's obligations under TRAI's regulations; no platform can register for you without your Letter of Authorisation. See the 140 number series guide for steps and penalties.
What does Digital Patron charge on top of the platform?
A one-time build fee from $599 (single flow) to $6,000+ (multi-flow, CRM-integrated), billed in USD and invoiced in INR with GST for Indian clients. Platform usage is billed by the provider. Our offices are in Gurugram and Mohali.
Sources (checked 14 October 2026)
- Bolna pricing: bolna.ai/pricing (6.00¢ / Rs 5.52 per minute; about 4.5¢ on larger top-ups; Pilot $500 for 12,000 and $300 for 6,500 minutes; 25 concurrency; $5 free credits; BYOK; "10+ vernacular Indian languages")
- Bolna, "Buy Phone Numbers for Your Bolna Voice AI Agents": bolna.ai/docs (US and India; Twilio, Plivo, Vobiz; $5 a month; compliance approval and KYC)
- Bolna, "How to Get 140 & 160-Series Phone Numbers in India": bolna.ai/docs (Vobiz for 140, Plivo for 160; DLT mandatory; Rs 5,900; activation sequence)
- Bolna, "Routing Calls Through Indian Servers": bolna.ai/docs (Plivo only; Deepgram hi/multi-hi/en-IN; Sarvam, Azure, ElevenLabs, Smallest, Cartesia; Azure OpenAI; BYO keys route via US)
- Bolna, Exotel integration: bolna.ai/integrations/exotel (inbound and outbound in India on your own ExoPhones)
- Vapi pricing: vapi.ai/pricing ($0.05 per minute hosting; models at cost; $82 to $129 per 1,000 minutes; free, Core $29, Pro $999 minimum, Premier; concurrency and $10 per line; HIPAA $2,000 a month; carrier rates)
- Vapi docs, "Creating Free Phone Numbers": docs.vapi.ai/free-telephony (US area codes, inbound only, import for other countries)
- Vapi docs, multilingual support: docs.vapi.ai (transcriber providers and auto-detection)
- Vapi docs, Vapi Voices: docs.vapi.ai (30+ languages including Hindi in v1; 40+ with auto-detection in v2); ElevenLabs provider page: docs.vapi.ai (Hindi on Flash v2.5, Multilingual v2, v3)
- Retell pricing: retellai.com/pricing ($0.055 voice infra; TTS $0.015 to $0.10; LLM per-minute table; telephony $0.015; SIP no charge; numbers $2; 20 free concurrency then $8; $10 credit; SOC 2, HIPAA-ready; add-ons)
- Retell docs, "Purchase a Retell-managed US or Canada phone number": docs.retellai.com (US and Canada only; $2 and $5; custom telephony or import for other countries); custom telephony: docs.retellai.com (SIP trunking to sip.retellai.com)
- Retell, Hindi language page: retellai.com/languages/hindi ("55+ languages"; unquantified latency claim); Retell blog on supported languages: retellai.com/blog ("31+")
- Digital Patron: AI voice agents ($599 to $6,000+), AI agents, pricing, free audit and the 140 number series guide
