Datasets:

Ajax102
/

OmniCap-400M

language:
  - en
  - zh
license: mit
multilinguality: multilingual
size_categories:
  - 100M<n<1B
task_categories:
  - image-to-text
  - text-to-image
tags:
  - image-text-pairs
  - large-scale
  - multimodal
  - captioning
  - retrieval
annotations_creators:
  - machine-generated
source_datasets:
  - web-scraped

OmniCap-400M

OmniCap-400M is a large-scale, general-purpose image-text dataset containing 400 million diverse image-caption pairs collected from the open web. It is designed to support a wide range of multimodal research tasks, including vision-language pretraining, image captioning, cross-modal retrieval, and text-to-image generation.

Each entry includes rich metadata to facilitate filtering, deduplication, and analysis.

Dataset Structure

The dataset is stored in Apache Parquet format and contains the following fields:

Field	Type	Description
`url`	string	The source URL of the image.
`md5`	string	MD5 hash of the image URL (for deduplication).
`width`	int32	Width of the image in pixels.
`height`	int32	Height of the image in pixels.
`blip_caption`	string	Machine-generated caption using BLIP.
`caption`	string	Raw textual context associated with the image (e.g., alt text, surrounding HTML text).
`query`	string	Keywords for web search.

⚠️ Note: This dataset contains web-crawled data. Users are responsible for complying with the terms of use of the source websites and applicable laws.

Intended Use

Pretraining or fine-tuning multimodal models (e.g., CLIP, BLIP, LLaVA).
Training text-to-image diffusion models with improved caption quality.
Building cross-modal search systems.
Studying bias, safety, and robustness in large-scale vision-language data.

License

MIT License.

Citation

If you use this dataset in your research, please cite it as:

@dataset{ajax2026omnicap,
  author = {Ajax102},
  title = {OmniCap-400M: A Large-Scale General-Purpose Image-Text Dataset},
  year = {2026},
  publisher = {Hugging Face},
  journal = {Hugging Face Datasets},
  url = {https://huggingface.co/datasets/Ajax102/OmniCap-400M}
}