Head to head
AssemblyAI vs Deepgram
As a speech-to-text API, Deepgram rates higher on the APIbenchmarks Index, 87.5 to 86.9, a 0.6-point gap. Here is how they compare on each criterion.
Criterion by criterion
| Criterion | AssemblyAI | Deepgram |
|---|---|---|
| Documentation & DX | ||
| Reliability | ||
| Ecosystem & SDKs | ||
| Accessibility | ||
| APIbenchmarks Index | 86.9 | 87.5 |
Specifications
| AssemblyAI | Deepgram | |
|---|---|---|
| Best for | Accurate STT plus audio intelligence | Real-time streaming STT for voice agents |
| Free tier | $50 one-time credit | $200 credit, no card |
| Pricing | Per minute (usage-based) | Per minute (usage-based) |
| Official SDKs | 7 languages | 9 languages |
Is AssemblyAI better than Deepgram?
On the APIbenchmarks Index, Deepgram rates higher (87.5 vs 86.9). It leads on the four weighted criteria, but price is reported separately, so the best choice still depends on your budget.
Verdict in one line
Deepgram leads by 0.6 points (87.5 vs 86.9) and wins 2 of 4 criteria; AssemblyAI wins 2.
Winner by criterion
| Criterion | Winner | ||
|---|---|---|---|
| Documentation & DX | 92 | 90 | |
| Reliability | 82 | 84 | |
| Ecosystem & SDKs | 83 | 82 | |
| Accessibility | 90 | 95 |
Choose AssemblyAI if… / choose Deepgram if…
- →documentation & dx matters most to you (92 vs 90)
- →ecosystem & sdks matters most to you (83 vs 82)
- →your use case matches its focus: accurate stt plus audio intelligence
- →reliability matters most to you (84 vs 82)
- →accessibility matters most to you (95 vs 90)
- →you need broad SDK coverage (9 official SDKs vs 7)
- →your use case matches its focus: real-time streaming stt for voice agents
Pricing side by side
- Model
- Per minute (usage-based)
- Free tier
- $50 one-time credit
- Free credits$50 free
- Universal-2 (async STT)$0.15/hr
- Universal-3 Pro (async STT)$0.21/hr
- Universal-Streaming$0.15/hr
- Voice Agent API$4.50/hr ($0.075/min)
- EnterpriseCustom
- Model
- Per minute (usage-based)
- Free tier
- $200 credit, no card
- Pay As You Go$0.0077/hr pre-recorded; $0.0048/min streaming (Nova-3 monolingual)
- Growth$0.0065/hr pre-recorded; $0.0042/min streaming (Nova-3 monolingual)
- EnterpriseCustom
- Aura-2 Text-to-Speech$0.030 / 1,000 chars (PAYG); $0.027 (Growth)
- Voice Agent APIFrom $0.075/min (PAYG); $0.068/min (Growth)
Vendor-published pricing, verified 2026-06-27 (AssemblyAI) and 2026-06-27 (Deepgram).
SDK and language coverage
Both · 6
PythonJavaScript / TypeScriptJava (maintenance)Go (maintenance)REST APIWebSocket streaming API
Only AssemblyAI · 1
Microsoft Power Platform connector
Only Deepgram · 3
.NET / C# (Deepgram NuGet)Rust (community SDK)CLI tool
Strengths and weaknesses
- +Strong English accuracy, Universal-2 ~6.68% WER beats Whisper large-v3 (~7.88%) in published comparisons
- +Very low base price ($0.15/hr async), far cheaper than Amazon Transcribe (~$1.44/hr) for comparable English STT
- +Clean, low-cleanup output: reliable punctuation, casing, proper nouns and alphanumerics (order numbers, etc.)
- –Add-on features (diarization, entity detection, redaction, translation) stack on the base rate, pushing effective cost well above the $0.15/hr headline (~$0.35/hr in independent estimates)
- –Cost becomes expensive at high audio volume for usage-heavy apps
- –Some users report inconsistent real-time latency under load, hurting predictability for live use cases
- +Very low streaming latency (sub-300ms), making it well-suited to real-time voice agents and live captioning
- +Among the cheapest per-hour STT pricing at scale ($0.0065-$0.0077/hr for Nova-3), with per-second billing (no minute rounding)
- +Clean, developer-friendly API with official SDKs and consistently praised documentation
- –Real-world accuracy on third-party benchmarks (Artificial Analysis ~18% WER) is far worse than vendor-claimed 5.26%, so headline numbers overstate hard-audio performance
- –Struggles relative to competitors on strong accents, overlapping speech, and noisy multi-speaker audio
- –Language support is narrower/less accurate for less-common and non-English languages
AssemblyAI vs Deepgram: questions
- Which has better documentation, AssemblyAI or Deepgram?
- AssemblyAI scores higher on documentation and developer experience: 92 vs 90 out of 100.
- Which is more reliable, AssemblyAI or Deepgram?
- Deepgram scores higher on reliability: 84 vs 82 out of 100.
- Do AssemblyAI and Deepgram have a free tier?
- AssemblyAI: yes ($50 one-time credit). Deepgram: yes ($200 credit, no card).
- How are AssemblyAI and Deepgram priced?
- AssemblyAI: Per minute (usage-based). Deepgram: Per minute (usage-based).
- Which has more official SDKs?
- Deepgram lists 9 official SDKs, AssemblyAI lists 7.