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LabelU
What it is
LabelU is an open-source platform for annotating image, video, and audio data, intended for work supporting complex data analysis and model training. Image tools cover 2D bounding boxes, semantic segmentation, polylines, and keypoints. Video and audio workflows support segmentation, classification, and information extraction. Users can bring in pre-annotated data for refinement, or use AI model services to detect and segment image objects, including batch jobs with live progress. Reference model servers include Florence-2, GroundingDINO with SAM ViT-B, and SAM 3. The platform imports annotation data from S3-compatible storage such as AWS S3 and MinIO, and exports JSON, COCO, and MASK formats. Local deployment uses Miniconda, Python 3.11, pip, and a local server at http://localhost:8000/. SQLite is included, with MySQL installation and migration also supported. The model server provides HTTP POST / and GET /health endpoints. Florence-2 and GroundingDINO with SAM ViT-B each require about 4GB VRAM; SAM 3 requires about 8GB and CUDA 12.6 or later. The project is licensed under Apache 2.0.
For and against
For
- Supports image, video, and audio annotation
- Can refine imported pre-annotations
- Imports from S3-compatible storage
- Exports JSON, COCO, and MASK
- Apache 2.0 licensed
Against
- Local setup requires Miniconda, Python 3.11, and pip
- SAM 3 requires about 8GB VRAM and CUDA 12.6+
- Deployment is self-hosted
The verdict
LabelU combines multimodal annotation, import and export options, and model-assisted image labeling in an open-source package. Teams should account for the local deployment steps and hardware requirements of the reference models.
Who it suits
LabelU suits teams annotating multiple data types for analysis or model training, especially those wanting self-hosted deployment and model-assisted labeling. Its listed local setup and model hardware requirements are relevant for teams preparing their own environment.
On the record
- AI assistance
- Users can load pre-annotated data in one click and refine it in the platform.github.com · read 2 Oct 2026
- AI assisted labeling
- Users can load pre-annotated data with one click and refine or adjust it.github.com · read 1 Oct 2026
- AI auto-annotation
- Image auto-annotation can detect and segment objects, with batch task annotation and real-time progress tracking.github.com · read 2 Oct 2026
- API
- The model server exposes a unified HTTP API with POST / and GET /health endpoints.github.com · read 1 Oct 2026
- Audio annotation
- Audio tools support audio segmentation, audio classification, and audio information extraction.github.com · read 1 Oct 2026
- Audio tools
- Audio annotation supports segmentation, classification, and information extraction.github.com · read 2 Oct 2026
- Database support
- SQLite is the documented default database, and MySQL can be installed as an optional dependency.github.com · read 2 Oct 2026
- Deployment
- The project documents local installation with Python 3.11 or later and running a local server at localhost:8000.github.com · read 2 Oct 2026
- Export formats
- The README lists JSON, COCO, and MASK among supported export formats.github.com · read 2 Oct 2026
- Image annotation
- Image tools include 2D bounding boxes, semantic segmentation, polylines, and keypoints.github.com · read 1 Oct 2026
- Image tools
- Image annotations include 2D bounding boxes, semantic segmentation, polylines, and keypoints.github.com · read 2 Oct 2026
- Intended users
- The README describes the platform as suited to annotation work supporting complex data analysis and model training.github.com · read 2 Oct 2026
- License
- The project is released under the Apache 2.0 license.github.com · read 2 Oct 2026
- Model requirements
- Florence-2 requires about 4GB VRAM, GroundingDINO plus SAM ViT-B about 4GB, and SAM 3 about 8GB with CUDA 12.6+.github.com · read 1 Oct 2026
- Object storage
- LabelU can import annotation data from S3-compatible storage such as AWS S3 and MinIO.github.com · read 1 Oct 2026
- Purpose
- LabelU is an open-source multimodal data annotation platform for image, video, and audio tasks.github.com · read 2 Oct 2026
- Reference models
- The project lists Florence-2, GroundingDINO with SAM ViT-B, and SAM 3 reference model servers, with GPU memory requirements stated for each.github.com · read 2 Oct 2026
- Storage integration
- LabelU can import files from S3-compatible storage, including AWS S3 and MinIO.github.com · read 2 Oct 2026
