We started Annotation.io because we'd lived the pain of bad training data firsthand. Since 2018, we've helped over 200 enterprises get high-quality labeled data — faster, more accurately, and at any scale.
Annotations delivered
Enterprise clients
Trained annotators
Countries covered
Our Mission
The gap between a good model and a great one is almost always in the data. We exist to close that gap — giving every team, from early-stage startups to global enterprises, access to annotation quality that was once only available to the best-resourced labs.
Six principles that guide every decision we make — from how we hire to how we deliver.
Every annotation goes through rigorous multi-stage quality review. We don't ship data we wouldn't trust ourselves.
Fast turnarounds are table stakes — what matters is delivering both speed and quality at the same time.
Our distributed workforce spans 40+ countries, giving us 24/7 coverage and deep domain expertise across regions.
SOC 2 Type II certified, GDPR compliant, and built with end-to-end encryption so your data stays yours.
We pay annotators fairly, offer flexible work, and invest in training so quality comes from motivated people.
Every annotation goes through rigorous multi-stage quality review. We don't ship data we wouldn't trust ourselves.
Seven years of building the infrastructure for trustworthy AI
Founded in San Francisco by Sarah Chen and Marcus Williams
First enterprise contract — 10M image annotations for an automotive OEM
Expanded to healthcare and medical imaging, built HIPAA-compliant infrastructure
Series A — $18M to scale our annotator network and quality platform
Reached 1 billion annotations delivered, opened APAC operations hub
Launched AI-assisted annotation tooling, cutting turnaround times by 40%
Series B — $52M to expand into video, 3D, and multimodal annotation
10,000+ active annotators across 40 countries, serving 200+ enterprise clients
Operators and researchers who've built annotation infrastructure at scale — now doing it for you.
SC
CEO & Co-Founder
Former ML lead at Google Brain. 12 years building large-scale data pipelines for computer vision research.
MW
CTO & Co-Founder
Ex-Amazon AI. Built annotation infrastructure powering Alexa's understanding of millions of daily utterances.
SC
VP of Operations
15 years managing global data operations teams. Previously scaled annotation workflows at Scale AI.
Whether you need 1,000 annotations or 100 million, our team is ready to help you get there.
