Compare Lab
Fish Audio vs Synthflow
Fish Audio is positioned as a developer speech API and creative voice workspace; paid TTS usage is metered in UTF-8 bytes. Synthflow is positioned as a visual voice-agent workflow platform sold through scoped deployments and partn
Fish Audio is positioned as a developer speech API and creative voice workspace; paid TTS usage is metered in UTF-8 bytes. Synthflow is positioned as a visual voice-agent workflow platform sold through scoped deployments and partner delivery. Start by deciding who owns the missing layers, then inspect the documented differences below.
Voice Engines and Full Platforms are different product categories. An underlying engine or framework is not a complete substitute for a deployed agent workflow.
16 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 | Fish Audio | Synthflow |
|---|---|---|
| Billing modelDifferent records | component-stack | custom-sales-led |
| Billing unitDifferent records | TTS: million UTF-8 bytes; ASR: audio hours; Agents: conversation minutes | Contract minimum per year; call seconds aggregate to minutes; five AI chat messages count as one usage minute |
| Bring your telephonyDifferent records | Yes | Yes |
| Bring your modelDifferent records | Yes | Yes |
| Warm transferDifferent records | Yes | Yes |
| HIPAA pathDifferent records | Unknown | Yes |
Your requirements & next steps
Your requirements
Ready-made / AI receptionist · Strict evidence mode
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TTS uses UTF-8 bytes, ASR audio hours, Agents minutes plus carrier/model/add-ons. Multiple products must not share a fabricated normalized unit.
Sales-ledcontract;call usage metered but exact unitrates and allowances negotiated.
Free TTS model and Agents promotional basic LLM scope are separate.
Starting commitment; complete contract cost remains unknown.
Each product keeps its own billing unit.
Rates,allowances andsimulationbilling come fromaccountagreement.
API access; managed numbers have separate rental and enterprise agreement may differ.
No complete current public contract rate and allowance schedule was established.
Real sessions consume balance including relevant carrier/model charges; no monthly included minutes.
No complete current public contract rate and allowance schedule was established.
Destination, transfer and selected model affect cost; no complete ceiling.
No complete current public contract rate and allowance schedule was established.
Rates have explicit event/destination scope, not a single maximum.
Reviewed current public offer; retain original billing scope and units.
Not yet researched against this buyer-critical field standard.
No complete current public contract rate and allowance schedule was established.
Call mix, destination, transfer time, selected model/token usage and separate speech products prevent a universal complete monthly/minute ceiling.
No complete current public contract rate and allowance schedule was established.
Call mix, destination, transfer time, selected model/token usage and separate speech products prevent a universal complete monthly/minute ceiling.
Research conclusion about cost completeness, not a vendor capability.
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.
Fish Audio
UTF-8 bytes and characters are not interchangeable for multilingual scripts.
TTS $15/M UTF-8 bytes; ASR $0.36/audio hour; Agents $0.06/min + applicable surcharges · V3.3 evidence review · TTS API reference; Voice Agents beta has separate minute-based billing
Excluded / confirm: Complete cost cannot be established from this reference. Call mix, destination, transfer time, selected model/token usage and separate speech products prevent a universal complete monthly/minute ceiling. · Phone destination surcharge, $1.20/month managed number, cold $0.015/min or warm $0.025/min post-transfer, non-basic LLM tokens; BYO carrier separate
TTS uses UTF-8 bytes, ASR audio hours, Agents minutes plus carrier/model/add-ons. Multiple products must not share a fabricated normalized unit.
Synthflow
Do not apply old self-service rates to a new contract.
Enterprise contracts from $30,000 annually · V3.3 evidence review · Enterprise contract starting annual commitment; scoped quote required
Excluded / confirm: Complete cost cannot be established from this reference. No complete current public contract rate and allowance schedule was established. · Account agreement and carrier/add-on terms require quote
Sales-ledcontract;call usage metered but exact unitrates and allowances negotiated.
The evidence overlap.
Both records have documented values for Product type, Call direction, Technical setup, Pricing model, Twilio, Call recording, Knowledge base / RAG, Function / tool calling, Interruption controls, Voicemail detection, Structured extraction, Webhooks and additional fields shown in Compare. 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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