Rev.ai

Rev.ai is the developer-facing API product from Rev.com, the US-based transcription company that has provided human and AI transcription services for over a decade. Where consumer products like Otter.ai and Fathom focus on meeting note-taking experiences, Rev.ai is designed for developers building speech recognition into their own applications.

The transcription accuracy is strong, particularly for English, benefiting from Rev.com's years of training data and model refinement. Speaker diarisation, which identifies and separates multiple speakers in a recording, is reliable enough for enterprise applications including call centre analytics, legal transcription, and media production.

The API is straightforward to integrate, with async processing for pre-recorded audio and streaming transcription for real-time applications. The async API accepts audio file URLs and returns completed transcripts via webhook, which is practical for batch processing workflows. The streaming API enables real-time caption generation and live transcription applications.

Custom vocabulary allows developers to specify domain-specific terms, names, and technical language that standard models might transcribe incorrectly. For applications in legal, medical, or technical fields with specialised vocabulary, this is a meaningful accuracy improvement.

At $0.02 per minute for async transcription, pricing is competitive for enterprise use and scales predictably based on usage volume. New accounts receive 300 free minutes for evaluation, which is enough to assess transcription quality for specific use cases.

Rev.ai is primarily relevant for developers and enterprises building transcription into applications rather than individuals looking for a meeting note-taking tool.