Universal-3.5 Pro is AssemblyAI's speech-to-text model served through its Sync API, returning a complete transcript with word-level timestamps in a single synchronous response for audio up to 20 minutes. It accepts WAV and compressed input (MP3, M4A, AAC, Ogg/Opus, FLAC, and WebM) and supports free-text prompting, keyterms, and conversation context to steer transcription toward domain vocabulary.
$0.0025
Share of requests served without a server error. Client errors (4xx) do not count.
Works with the OpenAI SDK pointed at our base URL. Every parameter is in the API reference.
Length of audio transcribed per day on NagaAI, counted since November 2026.
Universal-3.5 Pro is AssemblyAI's speech-to-text model served through its Sync API, returning a complete transcript with word-level timestamps in a single synchronous response for audio up to 20 minutes.
On NagaAI, Universal-3.5 Pro costs about $0.0025 per minute. You pay only for what you use, with no subscription.
It takes audio as input and returns transcription.
Create an API key, copy the model ID from the top of this page and send requests with the OpenAI SDK pointed at NagaAI. The API section on this page has a ready example.
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