Speech-to-Text APIs Compared

4 audio & voice tools compared on AiRecMark archive scores, five-dimension quality, published entry pricing and documented target fit.

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Deepgram leads this field with 85.1/100 — +0.6 pts over AssemblyAI.

All figures below are derived from the AiRecMark deterministic five-dimension evaluation archives. Pricing quotes are taken verbatim from each vendor's published plans.

Rank	Tool & Vendor	Quality / Perf / Usability	Score	Pricing	Best for	Spec
#1	DE DeepgramDeepgram	88 86 82	85.1	PAYG STT from $0.0043/min · TTS from $0.015/1k	Voice-API Product Builders	Inspect
#2	AS AssemblyAIAssemblyAI	88 86 78	84.5	Pay-as-you-go · Batch from $0.15-0.21/audio hr	Developers Building Voice Products	Inspect
#3	HU Hume AIHume AI	84 82 80	82.6	Free 10K TTS chars + 5 EVI min/mo · Starter $3	Voice-Agent Experience Designers	Inspect
#4	RE Resemble AIResemble AI	84 82 80	79.4	Flex $0 + PAYG credits (never expire) · Team $	Audio-Integrity & Security Teams	Inspect

Five-Dimension Matrix

Dimension	Deepgram	AssemblyAI	Hume AI	Resemble AI
Quality	88	88	84	84
Features	86	86	82	78
Usability	82	78	80	80
Performance	86	86	82	82
Value	82	82	84	72

Choose By Fit

Deepgram

Deepgram · 85.1/100

Choose Deepgram if you need voice-api product builders.

$200 free credit with no expiration
Nova-3 STT across 45+ languages with diarization

PAYG STT from $0.0043/min · TTS from $0.015/1k chars · Voice

Inspect Deepgram

AssemblyAI

AssemblyAI · 84.5/100

Choose AssemblyAI if you need developers building voice products.

Universal models with strong accuracy benchmarks
Full speech-intelligence stack (diarization, PII, sentiment)

Pay-as-you-go · Batch from $0.15-0.21/audio hr · Streaming f

Inspect AssemblyAI

Hume AI

Hume AI · 82.6/100

Choose Hume AI if you need voice-agent experience designers.

EVI senses user emotion and adapts in real time
Unlimited voice cloning on all plans

Free 10K TTS chars + 5 EVI min/mo · Starter $3/mo · Creator

Inspect Hume AI

Resemble AI

Resemble AI · 79.4/100

Choose Resemble AI if you need audio-integrity & security teams.

Detection covers audio, video and images
C2PA watermarking incl. SynthID checks

Flex $0 + PAYG credits (never expire) · Team $350/mo ($280 a

Inspect Resemble AI

Deterministic Takeaway

Deepgram tops the composite index at 85.1/100. Dimension leaders across the field — Quality: Deepgram, Features: Deepgram, Usability: Deepgram, Performance: Deepgram, Value: Hume AI. Every ranking and dimension value on this page is drawn from the archive-recorded AiRecMark tool archives as of 2026-09-17 and can be traced back to the public tool profiles.

Archive Record