Ultralytics YOLO datasets

The #1 cause of silent training failure is a malformed dataset — validate before training.

Fastest route: prepare data in Platform

1. Open Platform, create a dataset under Annotate, and choose its task.
2. Upload images, videos, ZIP/TAR archives, or NDJSON. Existing YOLO labels and COCO JSON can be imported; cloud-storage integrations can keep supported data in place.
3. Open an image in the fullscreen editor. Use manual tools for detect, segment, semantic, classify, pose, or OBB. For detect, segment, semantic, and OBB, switch to Smart mode to label with SAM or predictions from a compatible official/custom YOLO model.
4. Review the Classes, Charts, and Errors tabs, fix the split, and create a numbered dataset version before important runs.