Ultravox
This company has been acquired. See the summary for details.
Ultravox is a voice AI platform for developers that runs its own speech-native model, which takes in audio directly rather than converting it to text first. Teams build voice agents through a REST API, SDKs and a web console and connect them to phone lines over SIP or through Twilio, Telnyx, Plivo and other providers, for inbound and outbound calls. Billing is per minute on a pay-as-you-go plan, with a $100 per month Pro plan that removes the concurrency cap. Ultravox says it has been acquired by Inworld, and existing accounts keep working.
Ultravox pricing
| Plan | Price | Includes |
|---|---|---|
| Pay as You Go | $0/mo | $0.05/min; 30 free minutes; hard cap of 5 concurrent calls; SIP 0.5 cents/min; 1 custom voice clone; 2 RAG corpora; unlimited playground calls |
| Pro | $100/mo | $0.05/min; no hard cap on concurrent calls; SIP 0.48 cents/min; Outbound Call Scheduler; 5 custom voice clones; 20 RAG corpora |
| Enterprise | Quote | Custom pricing; priority concurrent calls; org support; response SLA; BAA for HIPAA customers |
- Contract: Pay as You Go has no monthly fee; billing terms for Pro and Enterprise are not stated
- Usage is $0.05 per minute on both self-serve plans, rounded to the nearest six seconds. The Pro plan adds no per-minute discount; it removes the 5-call concurrency cap and adds the Outbound Call Scheduler. SIP minutes are billed separately (0.5 cents/min on Pay as You Go, 0.48 cents/min on Pro), can be billed even when the agent is not connected to a caller, and ringing time is not billed. The pricing page labels prices ‘marked as annual rate’ without saying which ones, and the FAQ says Pro is billed in advance at the start of each period. A separate token price for ‘Threads’ ($2.00 per 1M uncached input tokens, $15.00 per 1M output tokens) is also listed; the page does not make clear which plan column it belongs to.
What it does
- Answers inbound calls
- Yes
- Places outbound calls
- Yes
- Books appointments
- Unconfirmed
- Warm transfer to a person
- Yes
- Text follow-up
- Unconfirmed
- Call recording
- Yes
- Transcripts
- Yes
- CRM sync
- Unconfirmed
- Keep your number (porting)
- Unconfirmed
- Spanish
- Unconfirmed
- Other languages
- Yes
- Web chat
- Unconfirmed
- API
- Yes
- Custom voice
- Yes
A January 2026 Ultravox blog post says agents can use any of Inworld’s pre-built voices in 15 languages, without naming them. The docs say built-in voices cover ‘all supported languages’ and do not list them, so Spanish is unconfirmed. Customers can also connect their own text-to-speech provider.
Integrations
As listed by Ultravox. Integrations not listed may still be possible through an API or Zapier.
Security and compliance
- Signs a HIPAA BAA
- Yes
- SOC 2
- Unconfirmed
- Discloses it's an AI
- Unconfirmed
Ultravox’s FAQ says it signs Business Associate Agreements for customers with HIPAA needs, on an Enterprise plan, and suggests starting with non-PHI data to confirm the use case before any protected health information is involved. Enterprise customers can also set automatic deletion of call data after each call. A BAA is not described for the self-serve plans.
“Unconfirmed” means Ultravox's public pages don't say either way. Rules for AI phone calls
Company
- Built for
- Small business, Enterprise
- Built on
- Ultravox’s own speech-native model (Ultravox v0.7) on its own inference stack, per the homepage. Built-in voices come from Inworld; ElevenLabs, Cartesia, OpenAI and other text-to-speech providers can be connected.
Sources
- Ultravox pricing pricing, features. Accessed October 21, 2026
- Ultravox homepage company, features, status. Accessed October 21, 2026
- Inworld: Inworld acquires Ultravox (09.30.2026) status, company. Accessed October 21, 2026
- Ultravox docs: FAQ pricing, compliance, features. Accessed October 21, 2026
- Ultravox docs: scaling and call concurrency pricing. Accessed October 21, 2026
- Ultravox docs: telephony overview features, integrations. Accessed October 21, 2026
- Ultravox docs: telephony platforms features, integrations. Accessed October 21, 2026
- Ultravox docs: supported providers integrations. Accessed October 21, 2026
- Ultravox docs: SIP guide features, pricing. Accessed October 21, 2026
- Ultravox docs: outbound calls features. Accessed October 21, 2026
- Ultravox docs: Outbound Call Scheduler features, compliance. Accessed October 21, 2026
- Ultravox docs: call transfers features. Accessed October 21, 2026
- Ultravox docs: voices features. Accessed October 21, 2026
- Ultravox docs: LiveKit integration integrations. Accessed October 21, 2026
- Ultravox blog: Pipecat integration integrations. Accessed October 21, 2026
- Ultravox blog: Inworld TTS 1.5 voices features. Accessed October 21, 2026
- About Ultravox company. Accessed October 21, 2026
- Ultravox terms of service company. Accessed October 21, 2026
- Ultravox: request a demo features. Accessed October 21, 2026
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