Tone vs Vapi

Tone9.3Visit Vapi8.9Visit

Higher score Tone #2 in AI Voice Agents 9.3/10 Free plan Free plan✓ 4 of 4 features Visit Tone

vs

Vapi #6 in AI Voice Agents 8.9/10 Paid ✓ 4 of 4 features Visit Vapi

• Tone fits best

  Teams wanting a complete open-source voice platform

• Vapi fits best

  Teams building and operating phone agents via API

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Side by side

Feature	Tone 9.3/10 Visit ↗	Vapi 8.9/10 Visit ↗
At a glance
Editor score	9.3	8.9
Ranking	#2 in AI Voice Agents	#6 in AI Voice Agents
Best for	Teams wanting a complete open-source voice platform	Teams building and operating phone agents via API
Pricing model	Free plan + paid	Paid
Starting price	$0.09 usage-based	$29/mo
Free plan	✓ (best)	—
Free trial	—	—
Deployment	Cloud, Self-hosted	Cloud, Mobile
Platforms	Web	Web, iOS
Integrations	20 integrations	20 integrations
Features Tone 4/4 · Vapi 4/4
Inbound calls	✓	✓
Outbound calls	✓	✓
Human handoff	✓	✓
Custom phone numbers	✓	✓
Specs
Supported languages	29 languages	Not checked yet
Concurrent calls	Not checked yet	10 calls
Our review
Pros	Self-hosting includes unlimited agents, calls, workflows, and integrations. Visual workflows support conditional branches and human handoff. Testing, call observability, and knowledge citations are built in.	Supports inbound, outbound, and web voice calls with live handoffs. Lets teams configure speech, language-model, and text-to-speech providers. Includes simulations, concurrency controls, monitoring, APIs, and SDKs.
Cons	Self-hosting requires teams to bring their own LLM, voice, and telephony. Cloud usage is billed per minute rather than through a fixed plan. Enterprise pricing is not specified in the published plan details.	Usage-based billing can include provider and telephony costs. Core limits included phone numbers and concurrent calls compared with Pro. Pro starts at $999 per month; Premier pricing is custom.
Our verdict	Tone is an open-source platform for teams building phone and other conversational agents. It supports inbound and outbound calls, web widgets, chat, and SMS, with a runtime, workflow builder, knowledge base, testing tools, and… Read the review →	Vapi is a developer platform for building, deploying, and monitoring voice AI agents across phone and web calls. Its API and SDK access, configurable speech and language-model providers, and call controls suit teams creating… Read the review →

Strengths and trade-offs

• Tone — where it wins

  • Self-hosting includes unlimited agents, calls, workflows, and integrations.
  • Visual workflows support conditional branches and human handoff.
  • Testing, call observability, and knowledge citations are built in.

  Where it doesn't

  • Self-hosting requires teams to bring their own LLM, voice, and telephony.
  • Cloud usage is billed per minute rather than through a fixed plan.
  • Enterprise pricing is not specified in the published plan details.

• Vapi — where it wins

  • Supports inbound, outbound, and web voice calls with live handoffs.
  • Lets teams configure speech, language-model, and text-to-speech providers.
  • Includes simulations, concurrency controls, monitoring, APIs, and SDKs.

  Where it doesn't

  • Usage-based billing can include provider and telephony costs.
  • Core limits included phone numbers and concurrent calls compared with Pro.
  • Pro starts at $999 per month; Premier pricing is custom.

• Tone9.3/10 · Free plan

  A full voice-agent toolkit with free self-hosting and cloud usage priced per minute.

  Visit ToneFull verdict →
• Vapi8.9/10 · Paid

  An API-driven platform for building and operating phone and web voice agents.

  Visit VapiFull verdict →