Label Studio solved a problem every AI team has and nobody wanted to talk about. Data labeling is painful, slow and expensive. They made it open-source, grabbed a massive developer community, and then monetised the enterprise layer on top. A $25 million Series A from Redpoint in 2022 validated that flywheel, and in 2023 the company behind it renamed itself HumanSignal. The open-core model is one of the few enterprise plays that actually works. Community does the marketing, enterprises pay the bills.
Founded
2019
HQ
San Francisco, CA
Total Raised
$30 million
Founder
Nikolai Liubimov, Max Tkachenko, Michael Malyuk
Status
Private (company now called HumanSignal)
Verified Oct 2026
Website
labelstud.ioTHE ORIGIN STORY
Michael Malyuk, Nikolai Liubimov and Max Tkachenko were working on ML projects and kept hitting the same wall. Getting clean, labeled training data was a nightmare, and every team was building the same janky internal tool.
In 2019 they founded Heartex and released Label Studio as an open-source project on GitHub, where it spread across ML teams worldwide. Malyuk became CEO and Liubimov CTO.
They built the enterprise product on top of the open-source core, and in June 2023 Heartex renamed itself HumanSignal.
WHAT THEY ACTUALLY DO
Open-core SaaS. The base Label Studio product is free and open-source — this drives adoption across thousands of ML teams.
Label Studio Enterprise is the paid tier, adding team collaboration, SSO, RBAC, automated ML-assisted labeling, and cloud storage integrations. Customers pay annual contracts.
The open-source moat makes sales cycles shorter because engineers already know the product before procurement gets involved.
THE PRODUCTS
Label Studio (open-source): a data annotation tool for text, image, audio, video and time-series data. Label Studio Enterprise, sold by HumanSignal, adds team management, automated labeling with ML models, SSO, audit logs and cloud storage connectors, plus tools for evaluating LLM output with human reviewers.
HOW THEY GREW
Developer-led growth driven by the open-source community. The founders seeded adoption by solving a real, unglamorous problem that every AI company has.
GitHub stars and community word of mouth replaced paid acquisition. Enterprise deals followed organic developer adoption inside those companies.
They focused on depth, supporting text, images, audio, video and time-series data, to become a single platform rather than a one-use-case tool. After the 2023 rebrand to HumanSignal they leaned into human review of generative AI output.
THE HARD PART
Competing with well-funded, narrower annotation tools like Scale AI and Snorkel, plus internal tools built by large tech companies. The challenge is convincing enterprises that an open-source tool is production-ready and supported — the classic open-core sales objection.
They also face the risk that cloud providers like AWS and GCP build native labeling tools directly into their ML platforms.
MONEY TRAIL
Series A
2022 · Led by Redpoint Ventures
$25M raised
WHO BACKED THEM
Redpoint Ventures led a $25 million Series A in May 2022, with existing investors Unusual Ventures, Bow Capital and Swift Ventures joining. The company said that brought its total raised to $30 million.
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Databricks
Both are core infrastructure for enterprise AI teams. Databricks handles data engineering and model training; Label Studio handles the data annotation that feeds those models. Complementary pieces of the same ML pipeline.
OpenAI
OpenAI relies on massive amounts of human-labeled training data. Label Studio represents the category of tooling — data annotation platforms — that makes large model training possible. Every OpenAI competitor and partner needs a solution to this problem.
Head-to-Head
Compare Label Studio vs another company.