Voice & audio · B-tier

AssemblyAI

Speech-to-text API with extras like summarization and content moderation on the transcript.

Open AssemblyAI Best AI voice and audio tools

Best for

Transcription APIs when you also want summary or moderation on the same call.

What it is

AssemblyAI is a speech-to-text API with add-ons that sit on the transcript, such as summaries and content flags. It competes with Deepgram for product transcription. Pick it when you want those extras in one API rather than a second model call.

sttapisummariesVoice & audio

Score breakdown

Capability 40%82
Ease 25%74
Value 20%76
Momentum 15%70

Pricing

Freemium

Starting price: check site

A free starting credit and usage-based plans. Check the dashboard for the current credit.

Dates

Released 2017 (year precision).

Added to StackPick 14 Oct 2026.

Alternatives

A-tier · 80

Deepgram

Product transcription, especially streaming audio, via an API.

A-tier · 80

OpenAI Audio

Transcription and straightforward TTS on an OpenAI key you already have.

B-tier · 74

Hume

Voice experiences where emotional delivery is the feature.

Questions

What is AssemblyAI best for?

Transcription APIs when you also want summary or moderation on the same call.

How much does AssemblyAI cost?

Freemium. Starting price: check site. A free starting credit and usage-based plans. Check the dashboard for the current credit.

What are alternatives to AssemblyAI?

Deepgram, OpenAI Audio, Hume are the alternatives we file next to it. Open a comparison when one exists.