OpenRouter records 19,941,437 monthly visits with -6.2% month-over-month growth and Paid pricing. Vapi records 662,301 monthly visits with -11.4% growth and Freemium pricing.
One API key for hundreds of AI models from every major provider
Build, test, and deploy production-grade voice AI agents over API
| Dimension / Metric | ||
|---|---|---|
| Official Domain | openrouter.ai | vapi.ai |
| Pricing Model | Paid | Freemium |
| Monthly Visits | 19.94M (19,941,437) | 662.3K (662,301) |
| MoM Traffic Delta | -1.33M (-6.2%) | -85.53K (-11.4%) |
| Primary Market & Share | 🇺🇸 United States (16.1%) | 🇺🇸 United States (44%) |
| Direct Visits / mo | 11.96M | 377.32K |
| User Rating | 4.8 | 4.5 |
| Supported Platforms | Website | Website |
One API key for hundreds of AI models from every major provider
Six hundred plus models for text, image, video, audio, transcription, embeddings, and reranking behind one OpenAI-compatible API.
Requests are rerouted to another provider on outages or rate limits by default, so you don't write custom retry logic.
The auto-router selects a model and provider per request using live marketplace performance and pricing data.
Track spend, tokens, and usage per model, provider, and team member in one place, including bring-your-own-key usage.
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.
Offers robust serverless inference and GPU clusters for open models, but features a narrower selection of proprietary models.
Offers robust serverless inference and GPU clusters for open models, but features a narrower selection of proprietary models.
Features adaptive LLM routing and automatic failover, but lacks OpenRouter's massive ecosystem of community-rated model endpoints.
Features adaptive LLM routing and automatic failover, but lacks OpenRouter's massive ecosystem of community-rated model endpoints.
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.
SpecialistDelivers exceptional inference speed and high-throughput performance for open models, but focuses primarily on hosted weights rather than multi-provider aggregation.
Free / Open-sourceProvides self-hosted and Python SDK control over 100+ LLMs, but requires setting up your own infrastructure.
SpecialistLow-cost serverless inference APIs for 200+ open models
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.
One unified API for 100+ AI models, with insurance when output disappoints
One unified API for 100+ AI models, with insurance when output disappoints
