ElevenLabs vs AssemblyAI: Speech-to-text API Comparison
This guide compares ElevenLabs Scribe v2 and AssemblyAI Universal-3 Pro, each company’s flagship STT models, to help you decide which could be a better fit for what you’re building.
TL;DR
Use ElevenLabs Scribe v2 if:
- You need strong accuracy across languages or have a globally distributed product.
- You want richer transcript metadata including entity detection, audio tagging (music, applause, etc).
- You want the option to build beyond batch transcription (realtime STT, TTS, agents, dubbing, or generated audio).
Use AssemblyAI Universal-3 Pro if:
- Your team wants more control over how transcripts are generated (through prompting).
- You want built-in transcript analysis (sentiment, topic detection, etc) rather than building and controlling that layer yourself.
- You have more than 5 audio channels with multiple speakers.
| Capability | ElevenLabs | AssemblyAI |
|---|---|---|
| Pre-recorded transcription | ✅ | ✅ |
| Realtime transcription | ✅ | ✅ |
| Word-level timestamps | ✅ | ✅ |
| Speaker diarization | ✅ | ✅ |
| 90+ languages on flagship STT model | ✅ | ❌ |
| Mixed-language transcription | ✅ | Limited |
| Built-in entity detection | ✅ | ❌ |
| Built-in audio tagging | ✅ | ❌ |
| Natural-language transcription prompting | ❌ | ✅ |
| Built-in transcript analysis | ❌ | ✅ |
| Multichannel diarization | ❌ | ✅ |
| Long-file parallel processing | ✅ | ❌ |
| Enterprise privacy controls | ✅ | ✅ |
Language support
Language support is one of the biggest differences. ElevenLabs Scribe v2 supports 90+ languages and mixed-language transcription, while AssemblyAI Universal-3 Pro is much more limited.
ElevenLabs Scribe v2
- ≤5% Word Error Rate (WER) across 36 languages with 90+ total languages supported.
- Detects and transcribes multiple languages in a single file automatically.
AssemblyAI Universal-3 Pro
- Supports 6 languages: English, Spanish, German, French, Portuguese, and Italian. To get broader language support, you need to fall back to other models (i.e. Universal-2).
- Supports limited code-switching (where speakers switch between languages in the same recording) for prerecorded audio. Developers can manually set up to two language codes, and one must be English.
For products with multilingual users, user-generated recordings, international support calls, or files uploaded without clean language labels, go with ElevenLabs Scribe v2.
Feature depth
Both APIs cover core STT features, but they differ in what comes back with the transcript and how much you can control what is returned.
| Feature | ElevenLabs Scribe v2 | AssemblyAI Universal-3 Pro |
|---|---|---|
| Keyterm prompting (1,000 keyterms) | ✅ | ✅ |
| Natural-language transcription prompting | ❌ | ✅ |
| Built-in audio tagging | ✅ | ❌ |
| Built-in entity detection | ✅ | ❌ |
| PII entity detection | ✅ | ❌ |
| More than 5 audio channels | ❌ | ✅ |
| Speaker diarization + multichannel audio | ❌ | ✅ |
| Text redaction | ✅ | ✅ |
| Audio redaction | ❌ | ✅ |
Use ElevenLabs when you want the transcript to contain rich metadata, including entities, audio events, timestamps, and multilingual transcription directly from the STT call. This makes the transcript easier to use for agents and other workflows downstream.
AssemblyAI gives you control over how the transcript is created and may be a good fit when you have more than 5 audio channels.
Workloads and concurrency
The two platforms handle long files differently.
| Batch workload capability | ElevenLabs Scribe v2 | AssemblyAI Universal-3 Pro |
|---|---|---|
| Batch transcription API | ✅ | ✅ |
| Async webhooks | ✅ | ✅ |
| Long-file parallel processing | ✅ | ❌ |
| Automatic splitting for files over 8 minutes | ✅ | ❌ |
If you want long batch files to come back faster without managing chunking yourself, use ElevenLabs. It splits longer files and processes them in parallel while AssemblyAI runs transcription through async jobs that queue against your account limits.
Pricing
Both platforms have similar base pricing. For teams building beyond transcription, total cost may also include TTS, agents, dubbing, voice cloning, add-ons, and any extra vendors needed to ship the product.
| Feature | ElevenLabs Scribe v2 | AssemblyAI Universal-3 Pro |
|---|---|---|
| Batch transcription | $0.22/hour | $0.21/hour |
| Realtime transcription | $0.39/hour | $0.45/hour for Universal-3 Pro Streaming |
| Keyterm prompting | $0.05/hour | $0.05/hour |
| Entity detection | $0.07/hour | $0.08/hour (speech understanding API) |
| Speaker diarization | No extra charge | $0.02/hour |
| Voice agent API | See agent pricing | $4.50/hour |
Pricing changes over time, so check each provider’s pricing page before making a final decision.
ElevenLabs includes speaker diarization in the base product, so teams that need diarization see a lower effective cost with ElevenLabs Scribe v2.
Beyond speech-to-text
If your product roadmap may require generated speech, voice agents, dubbing, or other audio features, it helps to start with an API that can grow with you.
ElevenLabs Scribe v2 integrates into a broader voice platform:
- Text to Speech: natural-sounding TTS in 70+ languages, with voice cloning and voice generation.
- Agents: conversational voice agents with tools for building, launching, monitoring, and evaluating agents.
If you want the option to expand beyond STT or are building a larger voice product, ElevenLabs is the clear choice. You can start with Scribe v2 for STT and add any combination of TTS, agents, dubbing, or generated audio later without bringing in another voice vendor.
Summary
| If you care about… | ElevenLabs | AssemblyAI |
|---|---|---|
| Broad language coverage | ✅ | ❌ |
| Mixed-language audio | ✅ | Limited |
| Rich transcript metadata | ✅ | ❌ |
| Long-file parallel processing | ✅ | ❌ |
| Expanding into voice agents or TTS | ✅ | Limited |
| Natural-language transcription prompting | ❌ | ✅ |
| Built-in transcript analysis | ❌ | ✅ |
| Multichannel diarization | ❌ | ✅ |
| Audio redaction | ❌ | ✅ |
Try ElevenLabs STT for free
- Get started with 10k free credits
- Contact sales for high-volume usage, voice agents, or enterprise SSO
FAQ
Which is better for speech-to-text?
It depends on your use case. If you only need transcription, we recommend testing both APIs on your audio. If you need broad language support or if STT is part of a real-time voice product or agent workflow, ElevenLabs is likely the better fit.
Which API should I use for voice agents?
ElevenLabs is a stronger fit for voice agents because developers can build across STT, realtime, TTS, and agents all in one platform.
Should I use one provider for STT and another for TTS?
You can, but using one platform can simplify development. ElevenLabs gives developers speech-to-text, text-to-speech, and agents in the same voice platform, which can reduce integration work for end-to-end voice products.
Can I try ElevenLabs for free?
Yes! ElevenLabs gives 10,000 free credits on signup with no credit card required, enough to test Scribe v2 transcription, TTS, voice cloning, and other APIs in the platform.
Can I use ElevenLabs for real-time transcription?
Yes! ElevenLabs Scribe v2 Realtime returns partial transcripts in approximately 150ms.
