AssemblyAI

Speech-to-text API with summarisation, audio intelligence and streaming

AI Audio & MusicFree planOverseasβ˜…β˜…β˜…β˜†β˜† 3.0

What is AssemblyAI?

AssemblyAI is a developer-facing speech API. It handles asynchronous transcription of uploaded audio and video, and low-latency streaming for live audio, then layers audio intelligence on top: summarisation, sentiment, topic detection, entity extraction, speaker labels and content moderation. Models are named and versioned, so you can pin a specific one and reason about what changed between releases. It is a building block rather than an application, delivered through REST endpoints, SDKs and webhooks with usage metered by audio hour, which suits teams embedding transcription into their own product.

Last updated: 2026-09-20. This site only provides an index; for exact features, pricing, and licensing, see the official website.

Key features

  • Asynchronous transcription of audio and video files through an API
  • Real-time streaming transcription for live audio input
  • Speaker diarisation that labels who spoke and when
  • Summarisation, sentiment, topic detection and entity extraction
  • Named, versioned speech models that can be pinned per request
  • SDKs, webhooks and broad audio format support

Pros & cons

Strengths

  • Accuracy on clear speech is strong and improving steadily
  • Intelligence features save building separate analysis steps
  • Usage-based pricing is easy to forecast for a product

Watch out for

  • It is an API only, with no editing interface of its own
  • Costs scale directly with the hours of audio processed
  • Very noisy or strongly accented audio still needs review

Best for & use cases

transcription inside apps, call analytics, meeting notes and media subtitling

If you're comparing similar products, check the alternatives below, or browse all tools in the AI Audio & Music category.

FAQ

Is there a user interface?

Only a dashboard for managing keys, usage and test runs. The product is designed to be called from code, so if you want a click-and-download transcription page you are better served by a consumer tool.

What are the audio intelligence features?

Optional add-ons that run after transcription: summaries, sentiment, topic labels, entity extraction and moderation. They save you from running a separate text pipeline over the transcript.

How is it priced?

By audio hour, with the intelligence and streaming features costing more than plain transcription. Estimate your monthly volume first, since a chatty product can accumulate hours faster than expected.