Open Source Data Annotation Tool
Labeled data is the real asset in any ML project - the model is replaceable, but the thousands of hours of human judgment poured into the annotations are not - and routing that work through a hosted tool means your proprietary data and the labels you paid for live on someone else's platform. The open source tools here run the labeling workflow for images and text on infrastructure you control, so the dataset, the annotations, and the process that produced them all stay with the team that built them.
Label Studio
Open source data labeling and annotation tool for text, images, audio, video, and time series
CVAT
Open-source data annotation platform for image, video, and 3D datasets with AI-assisted labeling
LabelMe
Offline image annotation tool with polygons, masks, and AI-assisted labeling
doccano
Open-source text annotation tool for collaborative labeling, classification, and sequence tasks
Argilla
Collaboration tool for AI engineers and domain experts to build high-quality datasets