--- title: "Speko vs Synthflow" description: "A sourced comparison of Speko (hosted phone agents, Router and Gateway) with Synthflow across product scope, telephony, routing, runtime ownership, observability and pricing." canonical: "https://speko.ai/speko-vs-synthflow" last-updated: "2026-11-10" --- > ## Speko page index > The complete index of every page on this site is at: https://speko.ai/llms.txt > Read it before exploring further. It lists the exact Markdown URL for every canonical HTML page. # Speko vs Synthflow Comparison Both are hosted voice agent platforms. The main difference is how you buy them. Short answer Choose Speko Agents to start self-serve at a published $0.09 per minute. It has phone numbers, inbound and outbound calls, SMS, transfers, testing and monitoring in one console. Choose Synthflow when an annual enterprise agreement with launch support and contact-center telephony integrations fits how your team buys. **By** Speko engineering **Published** November 10, 2026 **Updated** November 11, 2026 ## Which should you pick: Speko or Synthflow? ### Pick Speko Agents whenours - You want phone numbers, inbound and outbound calls, SMS and transfers in one console. - You want one price per minute, with speech-to-text, LLM and text-to-speech included. - You want to test an agent with simulated callers and score every real call. ### Pick Synthflow when - A hosted phone agent should be bought on an annual enterprise agreement scoped to call volume and phone system. - Agents should connect to an existing phone system, such as Five9, RingCentral or Twilio, or another SIP-compatible system. - Synthflow's engineers should help map calls, connect systems and launch, where the agreement includes it. [Get started free](https://platform.speko.ai/sign-in) [Book a demo](https://speko.ai/book) ## How do Speko and Synthflow compare? | | Speko Agents ours | Synthflow | | --- | --- | --- | | Who runs the agent | Speko hosts it | Synthflow hosts it | | Published price | $0.09/min Speech-to-text, LLM and text-to-speech included | No published rate Annual enterprise agreement; no rate by the minute | | Phone calls | Included: Speko numbers or your SIP trunk | Synthflow telephony, Twilio or SIP | | How you buy | Self-serve, no contract | Annual enterprise agreement | **See the full comparison, with sources** | Dimension | Speko Agents (hosted) Hosted phone agents | Synthflow | Speko Router + Gateway Model layer, your runtime | | --- | --- | --- | --- | | Category | Hosted voice agent platform with phone numbers, calls and SMS. | Hosted voice agent platform sold on annual enterprise agreements. | Voice model router. | | Scope | The whole agent: prompt, voice, tools, knowledge and the phone number live in the Speko console and API. Speko runs the conversation loop. | Voice and chat agents built in the Synthflow dashboard or API, each configured with either a Prompt Builder or a Flow Designer. | One API for STT, LLM and TTS model calls. It does not run the conversation loop. | | Telephony | Included. Inbound and outbound phone calls on a Speko number or on a number you already own (SIP trunk import); SMS on Speko numbers; blind and warm transfers to a human. | Synthflow Native Telephony, SIP trunking or approved enterprise telephony. Numbers can be bought through Synthflow, kept in Twilio, or imported over SIP on an Enterprise account. | Not included. Your runtime handles phone calls and WebRTC. | | Model routing | Measured selection and pre-response failover across STT, LLM and TTS. An agent can also pin providers, or run on a speech-to-speech model: Grok Voice 3.0 at the same per-minute rate, or GPT-Live, which adds its reasoning model's tokens at the provider's published rate plus 5%. | Agents are configured by prompt or by flow. Supported OpenAI models can run on the customer's own OpenAI or Azure OpenAI credentials. | Your application can pin a model, or let Speko pick from measured routes. | | Runtime ownership | Speko operates the agent runtime and the phone legs, records the call, persists transcripts and events, and finalizes a call report after hangup. The customer configures the agent. | Synthflow operates the agent platform and its own telephony infrastructure; the customer configures the agents. Where the agreement includes launch support, Synthflow's engineers map calls, connect systems and launch with the team. | Speko runs the routing API; you keep LiveKit, Pipecat or your own runtime. | | Observability and failover | Lifecycle events, a call report and a recording per call; signed workspace webhooks; call lists of up to 1,000 rows with a call window. | Call logs with transcript and recording, analytics on volume, outcomes and quality, and call-data export. | Response headers give the route, the reason, the failover count and the first-byte time. Failover happens before the response starts, not mid-stream. | | Benchmark transparency | An agent's default stack is computed from the same benchmark dataset that feeds the public boards at speko.ai/benchmarks; the picks are written into the agent at create time. | No sourced statement | Public voice benchmark boards at speko.ai/benchmarks; automatic selection ranks over the published snapshot. | | Pricing model | $0.09 per minute all-in for STT, LLM and TTS, billed from answer to hang-up; unanswered calls cost nothing. Calls on a Speko number add the carrier's charge plus 20%, at least $0.015 per minute outbound and $0.01 per minute inbound; calls over your own SIP trunk add nothing. A Speko number is $1 setup and $2 a month. $10 signup credit. | An annual enterprise agreement scoped to call volume and phone system. Synthflow's pricing page says it has no free plan or trial and no rate by the minute. Its phone-number docs list purchased numbers at $1.50 a month. | $0.09 per minute on Speko infrastructure for STT, LLM and TTS; phone calls on Speko numbers add the carrier's charge for the call, including its taxes and fees, plus 20%. Current terms are kept on the pricing page. | Synthflow sources: [Synthflow pricing](https://synthflow.ai/pricing) [Synthflow documentation](https://docs.synthflow.ai/getting-started) [Synthflow phone numbers](https://docs.synthflow.ai/phone-numbers) ## What does Synthflow cost compared with Speko? - Speko ours Speech-to-text, LLM and text-to-speech included $900 $0.09/min - Vapi Hosting only; models billed at cost on top $500 $0.05/min - Retell AI Range set by the components you choose $700 to $3,100 $0.07 to $0.31/min - Synthflow Annual enterprise agreement; no rate by the minute No published rate - LiveKit Cloud Agent hosting only; models billed on top $100 $0.01/min - Twilio ConversationRelay Speech relay only; voice minutes and your LLM on top $700 $0.07/min Monthly figures use the published per-minute rate only. They leave out plan fees, phone numbers, carriage and any models a vendor bills on top. **See every price term, with sources** | Platform | Per minute | Included | Telephony | Monthly fee | Source | | --- | --- | --- | --- | --- | --- | | Speko our product | $0.09 per minute, all-in | Speech-to-text, LLM and text-to-speech on Speko infrastructure. Billed per second from answer to hang-up; unanswered calls cost nothing. | Calls on Speko numbers add the carrier's charge for the call, including its taxes and fees, plus 20%, at least $0.01 per minute inbound and $0.015 per minute outbound. Calls over your own SIP trunk add nothing. | None. A Speko phone number is $1 setup and $2 a month for most numbers. | [speko.ai/pricing](https://speko.ai/pricing) | | Vapi | $0.05 per minute Vapi hosting, pre-paid | Vapi hosting. Speech-to-text, LLM and text-to-speech are passed through at the provider's cost on top. | Transport is charged by the carrier, not Vapi; Vapi's own SIP transport is listed as free. | None on the usage-only plan (1 included number, 4 concurrent calls). Core $29 a month; Pro $999 a month minimum; HIPAA $2,000 a month. | [vapi.ai/pricing](https://vapi.ai/pricing) | | Retell AI | $0.07 to 0.31 per minute for AI voice agents | Retell voice infrastructure at $0.055 per minute plus the selected text-to-speech and LLM components, each priced per minute. | Retell-provided numbers $0.015 per minute in the US; own SIP trunk or custom telephony at no charge from Retell. | None. A Retell phone number is $2 a month; 20 concurrent calls included, $8 per extra concurrent call a month. | [retellai.com/pricing](https://www.retellai.com/pricing) | | Synthflow | No rate by the minute, per Synthflow's pricing page; annual enterprise agreement | Scoped per contract. | Native telephony or SIP trunking, scoped per contract. | Quote only. Synthflow's pricing page says it has no free plan or trial. | [synthflow.ai/pricing](https://synthflow.ai/pricing) | | LiveKit Cloud | $0.01 per agent session minute after the included minutes on Ship and Scale | Agent hosting on LiveKit Cloud. Models are separate: each plan includes LiveKit Inference credits, and Ship and Scale then bill at model prices. | US local numbers: 1 free, then $1.00 a month on Ship and Scale. After the included minutes, US local inbound is $0.01 per minute and third-party SIP is $0.004 per minute on Ship, $0.003 on Scale. | Build $0 (1,000 agent session minutes); Ship from $50 (5,000); Scale from $500 (50,000); Enterprise custom. | [livekit.com/pricing](https://livekit.com/pricing) | | Twilio ConversationRelay | $0.07 per minute for ConversationRelay | The speech relay between a Twilio call and your own server. Twilio does not say on the pricing page whether speech is included in the rate; your LLM is billed by its own provider. | Twilio Voice, billed separately: US local calls $0.0085 per minute inbound and $0.0140 per minute outbound. | None. A US local number is $1.15 a month. | [twilio.com/voice/pricing/us](https://www.twilio.com/en-us/voice/pricing/us) | ## How do I switch from Synthflow to Speko? 1. ### 1Create the agent Create an agent in the Speko console, then paste your prompt and greeting. [Open the console](https://platform.speko.ai/sign-in) 2. ### 2Connect your tools Add calendars, CRMs and your APIs as tools, and upload a knowledge base. [See integrations](https://speko.ai/integrations) 3. ### 3Bring your number Import your number over a SIP trunk, or buy a Speko number. [Phone number setup](https://docs.speko.ai/guides/phone-agents) 4. ### 4Test, then go live Run simulated callers against the draft. Deploy when the checks pass. [How testing works](https://speko.ai/voice-agent-testing) ## Questions **What is the difference between Speko and Synthflow?** Choose Speko Agents when you want a hosted phone agent with numbers, inbound and outbound calls, SMS and transfers in one console, priced per minute. Choose Synthflow when a phone agent bought on an annual enterprise agreement, with launch support and contact-center telephony integrations, fits how the team buys. **How is Synthflow priced compared with Speko?** Speko Agents: $0.09 per minute all-in for STT, LLM and TTS, billed from answer to hang-up; unanswered calls cost nothing. Calls on a Speko number add the carrier's charge plus 20%, at least $0.015 per minute outbound and $0.01 per minute inbound; calls over your own SIP trunk add nothing. A Speko number is $1 setup and $2 a month. $10 signup credit. Synthflow: An annual enterprise agreement scoped to call volume and phone system. Synthflow's pricing page says it has no free plan or trial and no rate by the minute. Its phone-number docs list purchased numbers at $1.50 a month. **Does Synthflow include phone numbers and telephony?** Synthflow: Synthflow Native Telephony, SIP trunking or approved enterprise telephony. Numbers can be bought through Synthflow, kept in Twilio, or imported over SIP on an Enterprise account. Speko Agents: Included. Inbound and outbound phone calls on a Speko number or on a number you already own (SIP trunk import); SMS on Speko numbers; blind and warm transfers to a human. **Who runs the agent: Synthflow or my team?** Synthflow: Synthflow operates the agent platform and its own telephony infrastructure; the customer configures the agents. Where the agreement includes launch support, Synthflow's engineers map calls, connect systems and launch with the team. Speko Agents: Speko operates the agent runtime and the phone legs, records the call, persists transcripts and events, and finalizes a call report after hangup. The customer configures the agent. Speko Router + Gateway: Speko runs the routing API; you keep LiveKit, Pipecat or your own runtime. [Get started free](https://platform.speko.ai/sign-in) [Book a demo](https://speko.ai/book) You get $10 in credit when you sign up. Calls then cost $0.09 per minute. ## Notes - Synthflow facts are from its own pages, linked above, checked November 10, 2026. - Prices are from each vendor's own pricing page, checked November 11, 2026. - Speko Agents facts are from [Build a phone agent (Speko docs)](https://docs.speko.ai/guides/phone-agents) and the pricing page, checked November 11, 2026. Speko Router + Gateway facts are from the Speko infrastructure guide and pricing page. - An empty cell means that this page has no sourced statement for that cell. - The benchmark snapshot behind Speko routing is at [speko.ai/benchmarks/data.json](https://speko.ai/benchmarks/data.json). Related - [Voice agent platforms, runtimes and model routers](https://speko.ai/voice-agent-platforms) - [Speko vs Vapi](https://speko.ai/speko-vs-vapi) - [Speko vs Retell AI](https://speko.ai/speko-vs-retell) - [Speko vs LiveKit Agents](https://speko.ai/speko-vs-livekit) - [Speko vs Pipecat](https://speko.ai/speko-vs-pipecat) - [Speko vs Twilio ConversationRelay](https://speko.ai/speko-vs-twilio) - [Vapi alternatives](https://speko.ai/vapi-alternatives) - [Retell AI alternatives](https://speko.ai/retell-alternatives) - [Synthflow alternatives](https://speko.ai/synthflow-alternatives) - [Voice agent testing](https://speko.ai/voice-agent-testing) - [Voice agent monitoring](https://speko.ai/voice-agent-monitoring) - [Current model catalog](https://speko.ai/models) - [Voice agents by business](https://speko.ai/solutions) - [Speko pricing](https://speko.ai/pricing)