AssemblyAI, Inc.
Headquarters
San Francisco, CAFounded
2017CEO / Founder
Dylan FoxEmployees
51-200Funding
Series C — $115MProducts
1 product listedAvg. AI Score
8.1/10Website
assemblyai.com/
Profile updated
About AssemblyAI, Inc.
AssemblyAI is a speech AI company founded in 2017 by Dylan Fox and Ilya Gurevich, headquartered in San Francisco, California. The company builds and maintains speech recognition and audio understanding models, offering them as APIs that developers and enterprises use to transcribe and analyze spoken audio at scale.
The company's core product is a suite of APIs covering automatic speech recognition (ASR), speaker diarization, sentiment analysis, topic detection, and summarization of audio content. Customers span media, call center, and developer tooling sectors, using AssemblyAI's models to process recorded calls, podcasts, video content, and real-time audio streams. The company competes with offerings from Google, Amazon, and OpenAI in the speech-to-text market.
AssemblyAI raised a $50 million Series B round in 2022 and followed with additional funding, bringing total disclosed funding to approximately $115 million as of 2023. The company has grown its engineering and research headcount significantly since its founding, with staff concentrated in San Francisco and distributed remote roles. AssemblyAI trains its own speech models rather than relying solely on third-party foundation models, which it positions as a differentiator in accuracy and customization.
Specialties
Financials
Dated, source-cited figures. Estimates are marked.
Products by AssemblyAI, Inc.
All products by AssemblyAI, Inc. reviewed by our AI panel of experts.
How Our Review Panel Scores AssemblyAI, Inc.
Six independent reviewer personalities assessed AssemblyAI, Inc.'s product on their own terms. They landed within 0.4 points of each other, an unusually strong consensus.
Averaged across 1 reviewed product in our catalog. Scores are out of 10.
Competitive Landscape
Who AssemblyAI, Inc. competes with, and how they differ.
Deepgram is AssemblyAI's closest direct rival: both are developer-first speech-to-text APIs competing head-to-head on real-time streaming latency and per-audio-hour pricing, and both have layered voice-agent tooling on top of a core transcription engine.
1 product reviewed on TopReviewedOpenAI's open-source Whisper models and hosted Whisper API give developers a free or low-cost alternative to AssemblyAI's paid transcription API, trading AssemblyAI's speaker diarization, PII redaction, and audio-intelligence add-ons for Whisper's zero-cost open weights and broad language coverage.
Speechmatics targets large enterprises with on-premise and private-cloud deployment options and broader accent/language coverage claims, whereas AssemblyAI is cloud-API-only and leads with LLM-based audio intelligence features (LeMUR) layered on top of transcription.
1 product reviewed on TopReviewedGoogle Cloud Speech-to-Text bundles transcription into the broader GCP ecosystem at hyperscaler pricing and reliability, competing for enterprise customers who want a single vendor relationship rather than a point-solution API like AssemblyAI's.
ElevenLabs built its business on text-to-speech and voice cloning and only recently added a Scribe speech-to-text model, so it competes with AssemblyAI mainly for developers who want one vendor covering both transcription and voice generation rather than a transcription specialist.
1 product reviewed on TopReviewedCompany Timeline
Key milestones in AssemblyAI, Inc.'s history, with sources.
- Launch
Universal-3.5 Pro Async model released
AssemblyAI launched Universal-3.5 Pro, its flagship async speech-to-text model with native code-switching across 18 languages and improved speaker diarization, priced at $0.21/hour.
assemblyai.com - Launch
Universal-2-TF speech-to-text model released
AssemblyAI released Universal-2-TF, adding a neural text-formatting stage to its ASR pipeline that improved proper-noun accuracy by 24% and formatting accuracy by 14.8% over the prior model.
assemblyai.com - Funding
Series C — $50M led by Accel
AssemblyAI raised a $50M Series C led by Accel, with participation from Insight Partners, Y Combinator, Daniel Gross and Nat Friedman, bringing total funds raised to $115M.
assemblyai.com - Funding
Series B — $30M led by Insight Partners
AssemblyAI raised a $30M Series B led by Insight Partners, bringing total funds raised to just over $65M.
assemblyai.com - Funding
Series A — $28M led by Accel
AssemblyAI raised a $28M Series A led by Accel, with participation from Y Combinator, Stripe founders John and Patrick Collison, Nat Friedman and Daniel Gross.
techcrunch.com - Founded
AssemblyAI founded by Dylan Fox
Dylan Fox founded AssemblyAI as a solo founder in 2017, going through Y Combinator's Summer 2017 batch.
ycombinator.com
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