Best for
Best for developers who need accurate transcription, speech insights or voice agents behind a pay-as-you-go API.
- Small and mid-sized
- Enterprise
AI Voice & Speech Comparison
AssemblyAI vs. Speechmatics
At a glance
At a glance
Best for
Best for teams transcribing real conversations across accents and languages, including where the audio may not leave their own infrastructure.
- Small and mid-sized
- Enterprise
Cataleo does not name a winner. Both statements come from the vendors themselves.
Full Comparison
| Criterion | AssemblyAI | Speechmatics |
|---|---|---|
| Starting price | From $0.15 / hour of audio Pay-as-you-go, no subscription tiers. Pre-recorded speech-to-text is $0.15 / hour on Universal-2 and $0.21 / hour on Universal-3.5 Pro; streaming is $0.15 / hour on Universal-Streaming and $0.45 / hour on Universal-3.5 Pro Realtime; the Voice Agent API is $4.50 / hour, billed per second of connected conversation. Add-ons such as speaker diarization ($0.02 / hour) and medical mode ($0.15 / hour) are charged on top. | lower value From $0.129 / hour of audio Pro tier rate, billed to the second with no commitment. Volume discounts of 20% apply automatically above 500 hours per month for each speech-to-text type, with further discounts above 24,000 hours a year. One credit equals one dollar. |
| Free trial | $50 in free credits, no credit card required, covering up to 185 hours of pre-recorded or 333 hours of streaming transcription | Free tier with $100 in credit, no card required |
| Commercial use | Yes, usage-based | Yes, usage-based |
| Output | Transcripts, structured speech insights and live voice agent conversations | Transcripts, translations and synthesised speech |
| API | Yes, REST APIs and SDKs | Yes, batch and real-time speech-to-text, text-to-speech, translation and a management API |
| Languages | 99 languages on Universal-2 and 18 on Universal-3.5 Pro for pre-recorded audio; translation across 100+ languages | 55+ languages and dialects for speech-to-text; translation across 69 language pairs |
| Hosting | Not stated | Cloud, CPU or GPU containers, Kubernetes, on-premises virtual appliance, or on-device |
| Made in | Not stated | United Kingdom |
| Voice cloning | No, the platform covers speech recognition and voice agents rather than voice creation | No, the text-to-speech API ships four fixed voices, sarah and theo in British English and megan and jack in American English, and the documentation describes no custom or cloned voice; speed, pitch and emphasis are not adjustable either |
| Real-time use | Yes, streaming speech-to-text and a Voice Agent API, alongside batch transcription of pre-recorded files | Yes, streaming transcription returned in under a second, alongside batch transcription of recorded files |
| Speech-to-speech and dubbing | Yes, the Voice Agent API runs speech-to-speech conversations by orchestrating speech-to-text, an LLM and text-to-speech at one all-inclusive rate | Audio translation across 69 language pairs, returned as translated transcript rather than dubbed audio; a Voice Agent API is in early access |
| Editing and controls | Speaker identification, diarization, custom formatting, key phrase extraction and guardrails for PII redaction, profanity filtering and content moderation | Speaker diarization and identification, custom dictionary, language identification, background speech filtering, and speech intelligence for summaries, sentiment, topics and auto-chapters |
| Consent and trust | SOC 2 Type 2, ISO 27001, PCI-DSS and a HIPAA BAA included at no premium; EU region available at identical US pricing for GDPR | Data is not logged as standard; container, Kubernetes, virtual appliance and on-device deployment keep audio inside your own infrastructure |
| MCP-ready | stated Yes | No |
| Deployment | Cloud (SaaS), Browser-based | more entries Cloud (SaaS), Browser-based, On-premise |
| Support | Not stated | Email helpdesk |
| Onboarding | Documentation and knowledge base | Documentation and knowledge base |
| Company size | Small and mid-sized, Enterprise | Small and mid-sized, Enterprise |
| Integrations | Not stated | LiveKit, Pipecat, Vapi, Zapier |
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The short version
Key Differences
- Starting price AssemblyAI From $0.15 / hour of audio Speechmatics From $0.129 / hour of audio
- Free trial AssemblyAI $50 in free credits, no credit card required, covering up to 185 hours of pre-recorded or 333 hours of streaming transcription Speechmatics Free tier with $100 in credit, no card required
- Deployment AssemblyAI Cloud (SaaS), Browser-based Speechmatics Cloud (SaaS), Browser-based, On-premise
- Languages AssemblyAI 99 languages on Universal-2 and 18 on Universal-3.5 Pro for pre-recorded audio; translation across 100+ languages Speechmatics 55+ languages and dialects for speech-to-text; translation across 69 language pairs
- MCP-ready AssemblyAI Yes Speechmatics No
Every line is one datapoint from the table above, picked automatically. Nothing here is written text.
The trade-offs
Strengths and Limitations
AssemblyAI
Strengths
- Pay-as-you-go with no subscription and $50 in free credits to start
- 99 languages for pre-recorded transcription on Universal-2
- Compliance certifications and an EU region at no price premium
- Official MCP server exposes transcription and transcript search to AI agents
Limitations
- A developer API, not a ready-made studio or editor
- No voice cloning or voice creation
- Speech Understanding add-ons are billed on top of the base rate, so cost stacks per request
- Streaming is billed for as long as the connection stays open, not for the audio sent, and multichannel files are billed per channel
- Universal-3.5 Pro covers 18 languages against 99 on the older Universal-2
Speechmatics
Strengths
- 55+ languages with explicit accent, dialect and code-switching coverage
- Runs in the cloud, in containers, on-premises or on-device
- $100 in credit to start, with no card required
- Data is not logged as standard
Limitations
- A developer API rather than a ready-made voice studio
- Text-to-speech on the free tier covers English only
- The Voice Agent API is still in early access
- Volume discounts start at 500 hours a month, so small workloads pay the full rate
Plans
Pricing
AssemblyAI
- Pay-as-you-go From $0.15 / hour No subscription. Pre-recorded transcription $0.15 / hour on Universal-2 and $0.21 / hour on Universal-3.5 Pro, streaming $0.15 / hour on Universal-Streaming and $0.45 / hour on Universal-3.5 Pro Realtime, Voice Agent API $4.50 / hour. Add-ons are billed on top: speaker diarization $0.02 / hour, medical mode $0.15 / hour, keyterms prompting $0.05 / hour on Universal-3.5 Pro and included on Universal-2. Free accounts get 5 new streams per minute, pay-as-you-go accounts 100.
- Custom Not stated Contact sales for custom rate limits, higher concurrency and volume discounts. HIPAA BAA, PCI-DSS, ISO 27001 and SOC 2 Type 2 compliance at no premium, and an EU region at identical US pricing.
Speechmatics
- Free $0 $100 in credit, no card required. 55+ languages for speech-to-text, 2 concurrent real-time sessions and low-latency English text-to-speech.
- Pro $0.129 Per hour of audio, billed to the second with no commitment. 50 concurrent real-time sessions, 10 file jobs per second and email support.
- Enterprise Not stated Volume-based pricing that scales with usage, unlimited concurrency and no rate limits, custom models, custom vocabularies and formatting rules, and SaaS or on-premises deployment.
What users say
Review Scores · opens after launch
AssemblyAI
- Ease of use
- Not rated yet
- User interface
- Not rated yet
- Onboarding
- Not rated yet
- Support and service
- Not rated yet
- Value for money
- Not rated yet
- Features
- Not rated yet
No reviews yet. Be the first to review this tool. Every review is checked for fairness before it appears, and the vendor cannot have one removed.
Speechmatics
- Ease of use
- Not rated yet
- User interface
- Not rated yet
- Onboarding
- Not rated yet
- Support and service
- Not rated yet
- Value for money
- Not rated yet
- Features
- Not rated yet
No reviews yet. Be the first to review this tool. Every review is checked for fairness before it appears, and the vendor cannot have one removed.
Where this comes from
Where this comes from
AssemblyAI https://www.assemblyai.com · checked against the official source on 2026-08-30
Speechmatics https://www.speechmatics.com · checked against the official source on 2026-08-30
This table lists factual criteria taken from information the vendors publish themselves. For how we put it together, see the methodology.