AssemblyAI vs Deepgram
Best-in-class speech-to-text API — Universal models, 99 languages, low-latency streaming
vs. Enterprise-grade speech-to-text + voice agents — Nova + Flux + Aura TTS
Pricing tiers
AssemblyAI
Free Credits
$50 in free credits on signup. Full API access.
Free
Pay-as-you-go
Per-hour billing by model. No minimum.
$0 base (usage-based)
Enterprise
Custom contracts. SLA, private deployments, BAA.
Custom
Deepgram
Pay-as-you-go
$200 free credit. No minimums, no expiration.
$0 base (usage-based)
Growth
Starting $4K+/year prepay. Up to 20% savings.
$4000/mo
Enterprise
Custom. Data residency, dedicated support, on-prem option.
Custom
Free-tier quotas head-to-head
Comparing free-trial on AssemblyAI vs payg on Deepgram.
| Metric | AssemblyAI | Deepgram |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
Features
AssemblyAI · 11 features
- Advanced Prompting — Streaming with disfluency + code-switching + realtime diarization.
- Audio Intelligence — Sentiment, topic detection, summarization, entity detection, content safety, IAB…
- Auto Punctuation — Smart capitalization + punctuation.
- Keyterm Prompting — Boost accuracy for domain vocabulary.
- LeMUR (LLM framework) — Run LLMs over transcripts: Q&A, summary, action items.
- Medical Mode — Specialized for clinical + medical vocabulary.
- PII Redaction — Auto-redact credit cards, SSNs, addresses, emails.
- Pre-recorded Transcription — Upload audio/video URL or file → transcript.
- Realtime Streaming — WebSocket-based low-latency STT.
- Speaker Diarization — Identify who spoke when.
- Webhooks — Auto-notify when transcription finishes.
Deepgram · 15 features
- Aura TTS — Low-latency text-to-speech (<250ms).
- Data Residency — EU / US / custom regions.
- Diarization — Speaker identification.
- Intent Detection — Detect speaker intents automatically.
- Keyterm Prompting — Boost accuracy for proper nouns + domain terms.
- Language Detection — Auto-detect spoken language.
- On-Prem Deployment — Enterprise: run Deepgram in your infra.
- PII Redaction — Auto-redact sensitive info.
- Pre-recorded STT — Transcribe audio/video files.
- Sentiment Analysis — Per-segment sentiment scores.
- Smart Format — Numbers, dates, times auto-formatted.
- Streaming STT — Realtime WebSocket-based transcription.
- Summarization — Automatic transcript summaries.
- Topic Detection — Auto-extract conversation topics.
- Voice Agent API — Unified STT + LLM + TTS for voice bots.
Developer interfaces
| Kind | AssemblyAI | Deepgram |
|---|---|---|
| SDK | assemblyai-go, assemblyai (Node), assemblyai (Python), assemblyai (Ruby) | deepgram-dotnet-sdk, deepgram-go-sdk, deepgram-rust-sdk, @deepgram/sdk (Node), deepgram-sdk (Python) |
| REST | AssemblyAI REST API | Deepgram REST API |
| OTHER | Streaming WebSocket, Webhooks | Streaming WebSocket, Voice Agent API |
Staxly is an independent catalog of developer platforms. Outbound links to AssemblyAI and Deepgram are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.
Want this comparison in your AI agent's context? Install the free Staxly MCP server.