Comparison
Speko vs Retell AI
Speko Router is a voice model router for STT, LLM and TTS calls; Retell AI is a hosted phone-agent platform that runs the agent for you - they are not the same layer, so the useful comparison is which boundary your team wants to own.
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How do Speko and Retell AI compare?
Retell AI category, scope and billing statements were checked against the official sources below on . The table compares product boundaries, not overall quality. A dash means this site publishes no sourced statement for that cell.
| Dimension | Speko Router | Retell AI |
|---|---|---|
| Category | Voice model router. | Hosted phone-agent platform. |
| Scope | Compatible model calls for STT, LLM and TTS. It does not run the conversation loop. | Managed phone agents assembled from Retell-supported infrastructure and model components. |
| Telephony | Not included in the Router boundary. Telephony and WebRTC remain with the application runtime. | Published options include Retell carrier service and custom SIP, priced as separate components. |
| Model routing | The application can pin a model or request measured automatic selection from eligible routes. | The agent uses model and infrastructure choices supported by the Retell configuration surface. |
| Runtime ownership | Speko operates the routing API; the customer keeps LiveKit, Pipecat or a custom runtime. | Retell operates the phone-agent platform and runtime; the customer configures the agent. |
| Observability and failover | Route, reason, failover-count and first-byte headers. Failover is pre-response only, not mid-stream. | Call operations and logs are platform-managed within the supported component boundary. |
| Benchmark transparency | Public voice benchmark boards at benchmarks.speko.ai; automatic selection ranks over the published snapshot. | - |
| Pricing model | USD 0.09 per minute all-in on Speko infrastructure; current terms are kept on the pricing page. | Component pricing: voice infrastructure plus selected TTS, LLM, telephony and optional features. |
Retell AI sources:
Checked 2026-07-31
When to choose Retell AI
- The requirement is a managed phone-agent product rather than a standalone model-routing API.
- Telephony and agent operations should live in one hosted workflow.
- A component-based configuration and pricing surface fits how the team buys.
When to choose Speko
- Automatic routing considers only models in the published benchmark snapshot. If the request constraints leave no eligible candidate, the router returns no_candidate rather than selecting outside that snapshot.
- The route is decided when your session opens, not while you speak.
- A preview endpoint returns the provider Speko would pick for a language and objective, with its runners-up, before you send a request.
Method and provenance
Every Retell AI cell is copied from the sourced comparison this site maintains on the voice agent platforms page, where each statement carries its official source and check date. Speko cells are verified against the router source and the claim ledger this site builds from; the benchmark snapshot behind routing is published at benchmarks.speko.ai/data.json.
Choose the layer first. Compare products inside that boundary second.