Drop the dataset
Labels alone give class and box stats; add images for resolution and normalised-size histograms.
Datasets
Before training, look at the data. Drop YOLO, COCO or VOC labels (and optionally images) and get class frequency, boxes per image, box size and aspect-ratio distributions, and image resolution counts. The charts are SVG and can be saved for a report.
Loading the tool…
Labels alone give class and box stats; add images for resolution and normalised-size histograms.
Class imbalance, tiny boxes and extreme aspect ratios are the three things that most often explain a bad run.
Save any chart as SVG or PNG, or the whole summary as JSON or Markdown.
Boxes under 32 px on the training resolution are 'small' in COCO terms and need a higher input size or an anchor-free model to detect well.
A ratio above 10:1 between the most and least frequent class usually calls for oversampling or class weights; the tool prints the ratio.
If images vary widely in size, decide the training size from the box-size histogram at that size, not from the image sizes.
Yes: class folders or a labels CSV give per-class counts and image sizes.
Drop both split folders and the charts overlay the two.
JSONL or CSV with a label column gives label counts and text length distribution.