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AI Voice & Speech Comparison

AssemblyAI vs. Rev

At a glance

At a glance

AssemblyAI

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

Rev

Best for

Best for teams who need a transcript accurate enough to be relied on in court or in the record, with a human pass available on top of the machine one.

  • Freelancers
  • Small and mid-sized
  • Enterprise

Cataleo does not name a winner. Both statements come from the vendors themselves.

Full Comparison

Criterion AssemblyAI Rev
Starting price lower value 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. Free tier, then from $25.49 / seat / month The $25.49 Essentials rate is billed annually at $305.90 a year; paid monthly it is $29.99. Pro is $47.99 billed annually or $59.99 monthly. Human services are bought separately by the minute or page and are pooled across seats at account level. The Rev AI developer platform is billed per hour of audio instead, from $0.10 an hour on Reverb Turbo.
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 plan with 45 AI transcription and caption minutes a month, plus free Rev AI credits worth 5 hours of Reverb transcription
Commercial use Yes, usage-based Not stated
Output Transcripts, structured speech insights and live voice agent conversations Transcripts, captions, subtitles and case documents
API Yes, REST APIs and SDKs Yes, Rev AI for asynchronous and streaming speech-to-text, plus a human transcription API
Languages 99 languages on Universal-2 and 18 on Universal-3.5 Pro for pre-recorded audio; translation across 100+ languages 57+ languages for the Rev AI speech-to-text API; 37+ on the Pro subscription; human captions in English and Spanish and subtitles in 17 languages
Hosting Not stated Cloud or on-premises for the Rev AI platform
Voice cloning No, the platform covers speech recognition and voice agents rather than voice creation No, Rev works only on incoming speech and does not synthesise or clone voices
Real-time use Yes, streaming speech-to-text and a Voice Agent API, alongside batch transcription of pre-recorded files Yes, a streaming speech-to-text API for live audio alongside asynchronous transcription of recorded files; human services are turnaround-based rather than real-time
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 No dubbing or synthesised speech. Translation is text-only, at $0.002 to $0.025 per minute through the API depending on standard or premium, plus human subtitles at $6.49 to $15.99 a minute
Editing and controls Speaker identification, diarization, custom formatting, key phrase extraction and guardrails for PII redaction, profanity filtering and content moderation Transcript editor with clipping, multi-file evidence analysis with citations, image analysis, a document editor exporting to Word and PDF, AI templates for chronologies and affidavits, and API-side custom vocabulary, forced alignment with word-level timestamps, topic extraction and sentiment analysis
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 SOC 2, HIPAA, GDPR and PCI compliant with data encrypted at rest and in transit, a stated 99.99% uptime, and on-premises deployment for the API; the Unlimited subscription adds HIPAA and CJIS compliance, SSO and a dedicated specialist
MCP-ready stated Yes No
Deployment Cloud (SaaS), Browser-based more entries Cloud (SaaS), Browser-based, On-premise
Onboarding Documentation and knowledge base Documentation and knowledge base
Company size Small and mid-sized, Enterprise more entries Freelancers, Small and mid-sized, Enterprise
Integrations Not stated Clio

Compare more tools

Row where the values differ The small markers point at the lower number, the longer list or the stated feature. They describe the data, they are not a verdict.

The short version

Key Differences

  • Starting price AssemblyAI From $0.15 / hour of audio Rev Free tier, then from $25.49 / seat / month
  • 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 Rev Free plan with 45 AI transcription and caption minutes a month, plus free Rev AI credits worth 5 hours of Reverb transcription
  • Deployment AssemblyAI Cloud (SaaS), Browser-based Rev Cloud (SaaS), Browser-based, On-premise
  • Company size AssemblyAI Small and mid-sized, Enterprise Rev Freelancers, Small and mid-sized, Enterprise
  • Languages AssemblyAI 99 languages on Universal-2 and 18 on Universal-3.5 Pro for pre-recorded audio; translation across 100+ languages Rev 57+ languages for the Rev AI speech-to-text API; 37+ on the Pro subscription; human captions in English and Spanish and subtitles in 17 languages

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

Rev

Strengths

  • Human transcription at a stated 99%+ accuracy alongside the machine tier
  • Developer API priced per hour of audio, from $0.10 on Reverb Turbo
  • Runs on-premises as well as in the cloud on the API side
  • Free credits worth 5 hours of transcription, with no card required

Limitations

  • Speech-to-text only, no text-to-speech, dubbing or voice cloning
  • The subscription is built around legal and investigative work, which is dead weight for other uses
  • The free plan covers 45 minutes a month and English only
  • Human services are charged on top of the subscription rather than included

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.
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Rev

  • Free $0 45 AI transcription and caption minutes a month, English only, up to 5 files analysed at once, document editor and mobile app.
  • Essentials $25.49 Per seat per month billed annually at $305.90, or $29.99 billed monthly. Up to 3 seats, 5,000 AI minutes per seat per month in English and Spanish, up to 10 files analysed and 10% off human services.
  • Pro $47.99 Per seat per month billed annually at $575.88, or $59.99 billed monthly. Up to 5 seats, 10,000 AI minutes per seat per month across 37+ languages, up to 50 files analysed, image analysis, Clio integration and 15% off human services.
  • Unlimited Not stated Custom pricing. Unlimited seats and AI minutes, up to 500 files analysed, HIPAA and CJIS compliance, SSO and a dedicated specialist.
  • Rev AI pay-as-you-go $0.10 Per hour of audio on Reverb Turbo; Reverb is $0.20 an hour and foreign-language transcription $0.30 an hour across 56+ languages. Whisper Fusion and Large are $0.005 a minute. Human transcription through the API is $1.99 a minute. Insights are priced separately: language identification and forced alignment $0.003 a minute, topic extraction and sentiment analysis $0.0008 per 10 words, translation $0.002 to $0.025 a minute. Free credits equivalent to 5 hours of Reverb transcription to start.
  • Human services From $1.99 Per minute for human transcription and for human captions, with up to 15% off on a subscription. Legal rough drafts are $2.25 a page and legal premium transcripts $2.50 a page. Global subtitles run $6.49 to $15.99 a minute depending on the language, across 17 languages.
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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.

Rev

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

Rev https://www.rev.com · checked against the official source on 2026-09-04

This table lists factual criteria taken from information the vendors publish themselves. For how we put it together, see the methodology.