Label Studio

The most popular open-source data labeling platform for text, image, audio, and more

Editorially reviewedChecked Oct 2026How we review

mlops#data-labeling#annotation#open-source#training-data

Free plan Free trial API Self-hosted Teams

Toolglade’s take

A flexible, open-source annotation tool that handles text, image, audio, and more with configurable labeling interfaces, making it a strong default for building ML training data. The catch is that scaling to large teams and workflows often pushes you toward the paid enterprise tier.

Should you use Label Studio?

Best for: Data-centric ML teams · Multi-modal annotation projects · Teams wanting self-hosted labeling
Not ideal for: Teams needing an outsourced labeling workforce · Non-technical users wanting zero setup · Very small one-off tasks
Biggest strength: Open source and free to self-host
Biggest weakness: Self-hosting requires setup and maintenance
Pricing: Free plan, paid from $50/month
Top alternative: Labelbox · see all

Facts & pricing last checked October 2026. How we review

About Label Studio

Label Studio is HumanSignal's popular open-source data labeling platform for text, image, audio, video, and time series, free to self-host with managed cloud and enterprise tiers.

Label Studio is an open-source, multi-type data labeling tool used by a very large community of AI practitioners to create and refine training data. It handles many data modalities, including text, images, audio, video, and time series, and offers a configurable labeling interface plus a REST API exposing projects, tasks, annotations, predictions, storage, webhooks, and review workflows. Teams use it both to label raw data and to improve existing datasets, and increasingly to prepare data for fine-tuning LLMs and evaluating model outputs. The Community Edition is fully open source and free to self-host with all core labeling features, which has made it a default choice for data-centric ML teams. HumanSignal, the company behind it, also offers a managed Starter Cloud plan and an Enterprise edition that adds role-based access control, SSO, SOC 2 compliance, advanced analytics, workspaces, quality-assurance workflows, reviewer assignments, and SLAs. This tiering lets small teams start free and scale into governed, collaborative labeling operations.

Weighing your options?See how Label Studio compares to the alternatives.

TL;DR

Label Studio is HumanSignal's popular open-source data labeling platform for multi-modal data, free to self-host with managed cloud and enterprise governance tiers.

Company overview

Label Studio is the flagship open-source project of HumanSignal, used by a very large community of AI practitioners to label and refine training data. It has become a de facto standard for flexible, self-hostable annotation.

HumanSignal commercializes the project through a managed cloud and an Enterprise edition, funding continued open-source development while serving teams that need governance and scale.

Product features

Label Studio supports text, image, audio, video, and time series labeling with a configurable interface and a REST API covering projects, tasks, annotations, predictions, and review workflows. ML backends enable pre-labeling.

The Community Edition is free to self-host, while Enterprise adds RBAC, SSO, SOC 2 compliance, analytics, workspaces, and QA workflows for governed labeling operations.

Target market

Data-centric ML and AI teams that need flexible, self-hostable labeling for training data preparation, model evaluation, and human feedback across modalities.