Data annotation tools are software platforms used to label and tag data such as images, text, audio, and video to train machine learning and AI models. They enable teams to create structured datasets by applying classifications, bounding boxes, segmentation masks, transcripts, or metadata to raw data. The tools often include collaboration features, quality control workflows, and versioning to ensure labeling accuracy and consistency. Many data annotation platforms support automation through AI-assisted labeling to accelerate large-scale dataset creation. By transforming unstructured data into machine-readable formats, data annotation tools play a critical role in developing accurate and reliable AI systems. Compare and read user reviews of the best Free Data Annotation tools currently available using the table below. This list is updated regularly.
iMerit
AIMLEAP
Kili Technology
Roboflow
SuperAnnotate
Roora
Clarifai
Rosepetal AI
LightTag
V7
Diffgram
TrainingData.io
UBIAI
Label Your Data
Scalabel
Artificio Products Inc
Athina AI
Mindkosh AI
HumanSignal
Supervisely
BasicAI
Superb AI
CVAT
Label Studio
Encord
Datature
Sixgill
Segments.ai
Innotescus