AssemblyAI

AssemblyAI is a speech artificial intelligence (AI) company developing AI models capable of transcribing and understanding human speech. The company's speech models provide speech-to-text, speaker detection, sentiment analysis, chapter detection, personally identifiable information (PII) redaction, and more. AssemblyAI models can be accessed through its API for developers building AI applications that leverage voice data. Product examples include transcribing speech-to-text to analyze meetings, phone calls, podcasts, live audio streams, and other voice data. Assembly AI products are also available through its no-code playground with users uploading their own audio and video files for analysis by a range of models.

AssemblyAI products include the following:

• Speech-to-text—an automatic speech recognition model that transcribes in over seventeen languages and is trained on more than 1.1M hours of data
• Real-time transcription—conversations are transcribed with low latency for meetings, phone calls, and live events.
• Audio Intelligence—speech understanding capabilities, including sentiment analysis, PII redaction, auto chapters, and more
• LeMUR (Leveraging Large Language Models to Understand Recognized Speech)—a framework for applying LLMs to voice data, enabling users to generate summaries and recaps or ask questions about voice data

Speech-to-text, real-time transcription, and audio intelligence are available through the AssemblyAI API and priced by the length of the files analyzed:

• Speech-to-Text—$0.0001805 / second
• Real-Time Transcription—$0.0002083 / second
• Audio Intelligence—auto chapters $0.30 / hour, content moderation $0.25 / hour, entity detection $0.15 / hour, key phrases $0.06 / hour, PII redaction $0.20 / hour, PII audio redaction $0.05 / hour, sentiment analysis $0.12 / hour, summarization $0.06 / hour, and topic detection $0.20 / hour.

AssemblyAI serves over 200,000 developers and thousands of customers, including CallRail, Fireflies, and Spotify. AssemblyAI integrates with a number of other platforms, including LangChain, LlamaIndex, Semantic Kernel, Zapier, Rivet, AWS, Cloudflare, and Recall.

Headquartered in San Francisco, the company was founded in 2017 by Dylan Fox. Fox previously worked at Cisco as a machine learning engineer. AssemblyAI is a research company with an interdisciplinary team of scientists and engineers building and scaling speech AI models. AssemblyAI was a member of the Summer ’17 Y Combinator class and raised $120,000. On March 4, 2022, AssemblyAI announced a $28 million series A round led by Accel, with participation from Y Combinator, John and Patrick Collison, Nat Friedman, and Daniel Gross. Just a few months later, on July 14, 2022, AssemblyAI announced a series B round of $30 million led by software investor Insight Partners. On December 3, 2023, AssemblyAI shared it had raised $50M in Series C funding led by Accel with participation from Keith Block and Smith Point Capital, Insight Partners, Daniel Gross and Nat Friedman, and Y Combinator.