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Best Speech-to-Text APIs for Voice Agents and Transcription

Compare the best speech-to-text APIs for voice agents, call transcription, meeting intelligence, and multilingual ASR by latency, turn detection, accuracy, language coverage, and price.

Quick answer

Start with the use case: for Realtime voice agent with barge-in and turn-taking, pick Deepgram; for Voice agent where transcription quality beats cheapest streaming, pick AssemblyAI; for Want max accuracy or to self-host at scale, pick OpenAI Whisper; for Post-call analytics, meeting notes, or contact-center intelligence, pick AssemblyAI.

Decision matrix

A side-by-side view of type, cloning, languages, commercial licensing, and benchmark notes — every price is dated with its official source.

Deepgram
Type
ASR
Cloning
No
Free tier
Yes
Starting price
$0.0048/min
Languages
Nova supports 45+ languages; Flux has English and multilingual options
Commercial use
Commercial use under standard terms; self-hosted/on-prem available
Latency / accuracy
Flux is built specifically for voice agents
Benchmark note
Realtime voice-agent ASR
Price checked 2026-06-22
AssemblyAI
Type
ASR
Cloning
No
Free tier
Yes
Starting price
$0.15/hr
Languages
Universal-2 supports 99 languages; Universal-3 Pro/Streaming currently covers English, Spanish, German, French, Italian, and Portuguese
Commercial use
Commercial use under standard API terms
Latency / accuracy
Universal Streaming at $0.15/hour
Benchmark note
Transcription intelligence
Price checked 2026-06-22
OpenAI Whisper
Type
ASR
Cloning
No
Free tier
Yes
Starting price
Free (self-host) / $0.006/min API
Languages
99+ languages incl. Chinese
Commercial use
MIT license — free for commercial use
Latency / accuracy
Open repository and self-hosted control
Benchmark note
Open or self-hosted ASR baseline
Price checked 2026-06-12
Google Cloud Speech-to-Text
Type
ASR
Cloning
No
Free tier
Yes
Starting price
Usage-based
Languages
125+ languages
Commercial use
Commercial use under Google Cloud terms
Latency / accuracy
Streaming recognition returns results in real time over gRPC
Benchmark note
GCP-native enterprise ASR
Price checked 2026-06-22
ElevenLabs Scribe
Type
ASR
Cloning
No
Free tier
Yes
Starting price
Included in ElevenLabs plans
Languages
Multilingual real-time
Commercial use
Commercial use on paid ElevenLabs plans
Latency / accuracy
Scribe v1/v2 speech-to-text at $0.22/hour
Benchmark note
ElevenLabs voice-stack ASR
Price checked 2026-06-12

How to choose

  • For voice agents, test turn detection, interruption handling, partial transcript speed, and first response latency before you compare generic WER numbers.
  • For batch transcription, run a 30-minute sample set across clean calls, noisy calls, accents, and domain vocabulary before committing.
  • Watch add-on pricing carefully: diarization, redaction, keyterm prompting, sentiment, and summaries can stack on top of the base rate.
  • Separate voice-agent ASR from post-call analytics. The best real-time recognizer is not always the best meeting intelligence product.

Related paths

AI-citable summary
Last reviewed: 2026-06-22 by YixScout editorial team

What are the best speech-to-text tools and APIs?

The best speech-to-text tools and APIs include Deepgram, AssemblyAI, OpenAI Whisper, Google Cloud Speech-to-Text, and ElevenLabs Scribe. For real-time voice agents, start with Deepgram Flux when turn-taking, interruption handling, and first-response latency matter most. Pick AssemblyAI when you need transcript quality plus speech intelligence, Whisper when you want accuracy and self-hosting control, Google Speech-to-Text when your stack already lives on GCP, and ElevenLabs Scribe when you want ASR beside ElevenLabs TTS.

How should teams choose speech-to-text tools and APIs?

For voice agents, test turn detection, interruption handling, partial transcript speed, and first response latency before you compare generic WER numbers. For batch transcription, run a 30-minute sample set across clean calls, noisy calls, accents, and domain vocabulary before committing. Watch add-on pricing carefully: diarization, redaction, keyterm prompting, sentiment, and summaries can stack on top of the base rate. Separate voice-agent ASR from post-call analytics. The best real-time recognizer is not always the best meeting intelligence product.

Which speech-to-text tools and APIs have a free tier?

Deepgram, AssemblyAI, OpenAI Whisper, Google Cloud Speech-to-Text, and ElevenLabs Scribe offer a usable free tier or free entry, so you can evaluate them without paying. Paid plans typically start around $0.0048/min.

Which speech-to-text tools and APIs should I pick for my situation?

Realtime voice agent with barge-in and turn-taking → Deepgram; Voice agent where transcription quality beats cheapest streaming → AssemblyAI; Want max accuracy or to self-host at scale → OpenAI Whisper; Post-call analytics, meeting notes, or contact-center intelligence → AssemblyAI; Enterprise team already standardized on Google Cloud → Google Cloud Speech-to-Text.