Use the table below to compare each provider’s documented scope.
Before you decide
Decagon Voice vs Ultravox: buying questions
How should I compare Decagon Voice and Ultravox pricing?
Decagon Voice: Not publicly documented Ultravox: Pay-as-you-go and Pro plans combine a published per-minute rate with monthly plan fees; Enterprise is custom, and SIP is priced separately. Ask both vendors to quote the same expected workload, required channels, and implementation scope. Include required subscriptions and usage charges before comparing the total; the listed starting prices alone may cover different work.
Can Decagon Voice and Ultravox use my existing data?
The recorded knowledge and data sources for Decagon Voice include Not publicly documented. For Ultravox, they include Not publicly documented. Ask each provider to demonstrate access for the exact systems you use, with permissions, freshness, and failure behavior. A source missing from this directory is not proof that a provider cannot support it.
What should I test in a Decagon Voice vs Ultravox pilot?
Use the same representative calls, approved instructions, and escalation rules in both pilots. How does it handle interruption and uncertainty? Which actions can it complete, and which require approval? What context reaches a human during transfer? Record conversation quality, completed tasks, human handoffs, and total cost in the buyer worksheet. Check these specific cautions before launch: Decagon Voice: Public detail on voice stack, telephony, regions, languages, and rates is limited; validate in a scoped pilot. Ultravox: Open weights do not remove hosting, latency, safety, evaluation, voice, and telephony work. Review license and SLA.
direct speech-language interaction; open weights; hosted API; tools; realtime sessions
Team sizes
mid-market; enterprise
startup; mid-market; enterprise; developer
Call surfaces
voice; chat; email
phone / PSTN; API / SDK
Voice stack
Not publicly documented
Native speech-language model
Telephony
Not publicly documented
Not publicly documented
Call controls
Not publicly documented
Not publicly documented
Languages
Not publicly documented
Not publicly documented
Integrations
Not publicly documented
Not publicly documented
Knowledge and data
Not publicly documented
Not publicly documented
Pricing model
Not publicly documented
Pay-as-you-go and Pro plans combine a published per-minute rate with monthly plan fees; Enterprise is custom, and SIP is priced separately.
Pricing signal
Not publicly documented.
30 free minutes; $0.05/min pay-as-you-go; Pro $100/month; SIP about $0.005/min.
Free plan or trial
Not publicly documented
30 free minutes; open weights under published license.
What stands out
Decagon combines voice turn-taking and profile controls with concise human handoff summaries, MCP/API connectivity, and cross-channel CRM/helpdesk/knowledge sync.
Ultravox documents a native speech path without a separate ASR stage, then exposes both Console prototyping and REST/SDK integration with BYOT telephony.
Considerations
Public detail on voice stack, telephony, regions, languages, and rates is limited; validate in a scoped pilot.
Open weights do not remove hosting, latency, safety, evaluation, voice, and telephony work. Review license and SLA.
Decagon Voice: fit and scope
Support teams that need phone automation connected to CRM, helpdesk, knowledge-base, or CPaaS systems.
Decagon combines voice turn-taking and profile controls with concise human handoff summaries, MCP/API connectivity, and cross-channel CRM/helpdesk/knowledge sync.
Ultravox: fit and scope
Engineering teams that want direct speech processing and control over telephony or app transports.
Ultravox documents a native speech path without a separate ASR stage, then exposes both Console prototyping and REST/SDK integration with BYOT telephony.
Verify current pricing, limits, security, and required integrations directly with each provider before purchasing.
Evaluate language support in real calls
Test recognition, speech quality, interruptions, language switching, tool use, and human transfer with your own calls in the required language. Availability can vary by model, plan, and phone route.
DocsBot documents multilingual voice workflows and Japanese support. Verify the exact voice, phone path, and transfer behavior in your pilot. Review DocsBot language information ↗
Other providers’ language claims reflect cited vendor material; confirm Japanese and other required languages directly with each provider.
Listing does not imply endorsement or a performance guarantee. This directory is published by DocsBot. Editorial policy
Your business. Your shortlist.
Decagon Voice and Ultravox: which fits your call flow?
Start with your website. Answer a few focused questions, then get a personalized PDF with fit, trade-offs, alternatives and a pilot plan for your call flow.