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Cartesia vs Speechmatics
Cartesia is positioned as speech models for teams assembling a voice stack, with a separate managed-agent product. Speechmatics is positioned as recognition APIs with cloud and private-deployment choices for transcription-heavy pr
Cartesia is positioned as speech models for teams assembling a voice stack, with a separate managed-agent product. Speechmatics is positioned as recognition APIs with cloud and private-deployment choices for transcription-heavy products. Start by deciding who owns the missing layers, then inspect the documented differences below.
Voice Engines and STT are different product categories. An underlying engine or framework is not a complete substitute for a deployed agent workflow.
8 jointly documented catalog fields. This measures evidence coverage, not equivalent quality or an overall winner.
Test opening hours, booking conflicts and an unanswered transfer.
Start where the records differ.
Values and evidence states are compared together. Shared facts follow the differences; Unknown never means No.
| Decision point | Cartesia | Speechmatics |
|---|---|---|
| Billing unitDifferent records | TTS/STT credits; Managed Agents conversation minutes | Credits (1 credit = $1); product-specific per-hour rates, calculated to the second |
| Bring your telephonyDifferent records | Yes | Unknown |
| Bring your modelDifferent records | Yes | Not applicable |
| WebhooksDifferent records | YesAPI / webhook | YesUnknown |
| Billing modelShared state | component-stack | component-stack |
| Warm transferShared state | Unknown | Unknown |
Your requirements & next steps
Your requirements
Ready-made / AI receptionist · Strict evidence mode
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TTS/STT credit subscriptions and Managed Agents minute charges remain separate.
Credit billing: one credit equals $1; usage measured by product hours/seconds. This does not mean a character-priced TTS rate or flat agent minute rate.
Speech model credits and selected LLM/evaluation charges have separate scope.
Price page exposes a Pro 0.129 figure without a clear unit in captured content; exact model rate and enterprise commitment require confirmation.
Product-specific units preserved.
Billing currency versus usage unit kept distinct.
Plan allowances include separate agent prepayment; do not double-count as universal included voice minutes.
No fixed subscription number inferred from credit billing.
Separate credit and agent budgets; no arbitrary cross-product minute conversion.
Existing pre-August accounts have different transition grant.
Free allowances and product rates are available; old changelog, bandwidth trial and speech volume controls do not establish these current billing terms.
No forced per-minute bundle conversion.
LLM promotion ends October 1, 2026; quoted model/usage mix determines bill.
Buyer-selected component costs sit outside speech API usage.
Not yet researched against this buyer-critical field standard.
Not yet researched against this buyer-critical field standard.
Product mix, LLM promotion expiry, carrier routing and other metered components prevent a universal all-in ceiling.
Speech component credits and contract-specific workloads do not determine full voice-agent cost; external LLM/hosting/telephony unknown.
Product mix, LLM promotion expiry, carrier routing and other metered components prevent a universal all-in ceiling.
Speech component credits and contract-specific workloads do not determine full voice-agent cost; external LLM/hosting/telephony unknown.
Anyone with this link can view the encoded decision criteria.
Vendor documentation establishes a claim. Public model benchmarks are separate context, not measurements of these platforms.
Open saved comparison ↗What to verify together.
Cartesia
A speech credit plan is not a complete phone-call bill.
Managed Agents $0.06/min; Cartesia-provided-number telephony $0.014/min · V3.3 evidence review · Managed Agents base rate; carrier/model charges and prepaid plan balances separate
Excluded / confirm: Complete cost cannot be established from this reference. Product mix, LLM promotion expiry, carrier routing and other metered components prevent a universal all-in ceiling. · LLM tokens after promotional coverage; telephony and evaluation usage
TTS/STT credit subscriptions and Managed Agents minute charges remain separate.
Speechmatics
The lowest advertised batch price is not a real-time price.
Pro self-serve PAYG; Enterprise contract billing · V3.3 evidence review · STT exact-second metering billed in audio hours; no verified current complete rate schedule
Excluded / confirm: Complete cost cannot be established from this reference. Speech component credits and contract-specific workloads do not determine full voice-agent cost; external LLM/hosting/telephony unknown. · External LLM, orchestrator, telephony and application hosting
Credit billing: one credit equals $1; usage measured by product hours/seconds. This does not mean a character-priced TTS rate or flat agent minute rate.
The evidence overlap.
Both records have documented values for Product type, Technical setup, Pricing model, Published numeric pricing, Realtime / streaming audio, Published included concurrency at least, Checked within 30 days, Retained price snapshot. Matching availability does not measure behavior under your call conditions.
Run the same booking, tool failure and unsuccessful human-transfer cases. Record both outcomes and billable units before signing a deployment agreement.
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