Sendmux records 37 monthly visits with -98.3% month-over-month growth and Free pricing. Vapi records 662,301 monthly visits with -11.4% growth and Freemium pricing.
Give every AI agent a real inbox and one API to use it
Build, test, and deploy production-grade voice AI agents over API
| Dimension / Metric | | |
|---|---|---|
| Official Domain | sendmux.ai | vapi.ai |
| Pricing Model | Free | Freemium |
| Monthly Visits | 37 (37) | 662.3K (662,301) |
| MoM Traffic Delta | -2.2K (-98.3%) | -85.53K (-11.4%) |
| Primary Market & Share | 🇺🇸 United States (100%) | 🇺🇸 United States (44%) |
| Direct Visits / mo | 12 | 377.32K |
| User Rating | 4.2 | 4.5 |
| Supported Platforms | Website | Website |
Give every AI agent a real inbox and one API to use it
Provision mailboxes on verified domains or a shared myagent.mx address, with clean JSON output that strips signatures and quotes.
Send over HTTP or SMTP using the same mailbox credential as a Bearer token and SMTP password, with Idempotency-Key retries and attachment support.
Bind keys to providers, delivery groups, weights, and quota windows so traffic stays inside the boundaries you set.
Signed webhooks for delivery and receipt events, an SSE stream for live mailbox clients, and typed change polling for resync.
Build, test, and deploy production-grade voice AI agents over API
Configure speech recognition, an LLM reasoning layer and text-to-speech through one API instead of integrating several vendors separately.
The platform handles real-time audio streaming, interruption handling and call state so conversations feel natural and responsive.
Provision Vapi phone numbers or bring Twilio, Vonage or Telnyx, and support both inbound and outbound calling from the same agent.
Simulate calls before launch, then track transcripts, effectiveness metrics and compliance signals across every production call.
SpecialistProvides raw frontier language models and real-time multimodal capabilities, requiring custom scaffolding compared to Vapi's voice workflows.
SpecialistProvides raw frontier language models and real-time multimodal capabilities, requiring custom scaffolding compared to Vapi's voice workflows.
SpecialistOffers developer access to Gemini's powerful multimodal APIs, but lacks out-of-the-box telephony voice agent pipelines.
SpecialistOffers developer access to Gemini's powerful multimodal APIs, but lacks out-of-the-box telephony voice agent pipelines.
Industry leader in ultra-realistic voice cloning and text-to-speech, now offering robust conversational voice agent capabilities.
Industry leader in ultra-realistic voice cloning and text-to-speech, now offering robust conversational voice agent capabilities.
Provides ultra-low latency text-to-speech and managed voice agents via developer API, rivaling Vapi's audio speed.
Provides ultra-low latency text-to-speech and managed voice agents via developer API, rivaling Vapi's audio speed.
Delivers robust real-time speech-to-text and voice agent APIs, though with less telephony-specific orchestration than Vapi.
Delivers robust real-time speech-to-text and voice agent APIs, though with less telephony-specific orchestration than Vapi.
Collaborative inbox and email management for teams
Collaborative inbox and email management for teams
SpecialistProvides enterprise-grade speech-to-text and audio intelligence APIs, but lacks turnkey conversational voice agent telephony orchestration.
SpecialistProvides enterprise-grade speech-to-text and audio intelligence APIs, but lacks turnkey conversational voice agent telephony orchestration.
Email an AI assistant and let it run your schedules, inbox and CRM
The universal context engine connecting agents to data, tools, and models
Managed auth and 10,000+ tools for the agents you're building
Fast Apply and agent-tuned inference for coding agents
Fast Apply and agent-tuned inference for coding agents
Enterprise voice AI platform specializing in high-volume outbound and inbound phone calls with robust telephony integrations.
Enterprise voice AI platform specializing in high-volume outbound and inbound phone calls with robust telephony integrations.
