Dataset Card for MOMIJI

MOMIJI (Modern Open Multimodal Japanese filtered Dataset) is a large-scale, carefully curated public dataset of image-text–interleaved web documents. The dataset was extracted from Common Crawl dumps covering February 2024 – January 2025 and contains roughly 56M Japanese documents, 110B characters, and 249M images. Details of the collection and filtering pipeline will be described in a forthcoming paper.

Image-text–interleaved data is generally used to train large vision-language models (LVLMs) such as LLaVA-OneVision, Idefics 2, NVILA, and Qwen 2.5-VL. Using MOMIJI, we trained our proposed model Heron-NVILA-Lite.

Following OBELICS, we provide an interactive visualization that allows users to explore the contents of MOMIJI. The map shows a subset of 1M of the 56M documents.

Warning and Disclaimer: This content may unintentionally include expressions or information that some may find inappropriate. Please view it at your own discretion and responsibility.

Data Fields

Example (truncated):

{
  "docId": "CC-MAIN-20240518121005-20240518151005-00454_00091",
  "url": "https://tanaka-yuki.com/spring/post-10813/",
  "text_list": [
    "大学の卒業式には、男性ならスーツを選ぶ方がとても多いですが、どんなスーツを着用すればいいのか？と悩みますよね。",
    "...",
    "大学卒業式で男性はスーツが基本",
    "<image1>",
    "...",
    "安定感ならシングルデザイン",
    "<image2>",
    "..."
  ],
  "text": "大学の卒業式には、男性ならスーツを選ぶ方がとても多いですが、どんなスーツを着用すればいいのか？と悩みますよね.\n ...",
  "image_info": [
    {
      "placeholder": "<image1>",
      "url": "https://tanaka-yuki.com/wp-content/uploads/2022/12/collage-1-1.webp",
      "width": 1080,
      "height": 620,
      "original_width": 1080,
      "original_height": 620,
      "exif": "{}",
      "alt": "大学卒業式で男性はスーツが基本"
    },
    "..."
  ]
}

Each sample has five top-level fields:

Field	Type	Description
`docId`	`str`	Unique ID derived from the source Common Crawl ID
`url`	`str`	Source web URL
`text_list`	`list\<str\>`	Document text split into individual segments
`text`	`str`	Full text with image placeholders
`image_info`	`list\<dict\>`	List of image metadata: • `placeholder` (str) • `url` (str) • `original_width` / `original_height` (int) • `exif` (dict, optional) • `alt` (str, optional)

Size and Splits

MOMIJI contains about 56M Japanese web documents. Because images are provided only as URLs (no binary data), the dataset is roughly 150 GB.

MOMIJI Statistics

Metric	Value
Number of documents	56,119,639
Number of images	249,745,953
Total characters	109,980,725,957
Average characters/Doc.	1,959
Average images/Doc.	4.45

Below is a bar chart of document counts by number of images (documents with > 30 images are omitted for readability):

Permitted Use — Information Analysis Only

This dataset may be used exclusively for "information analysis" as defined in Article 30‑4 of the Japanese Copyright Act (non‑consumptive machine processing that does not aim at human enjoyment of the work).

Allowed

Training, evaluating and auditing machine‑learning models (e.g. LLMs, LVLMs, safety studies)
Automatic summarisation, text mining, statistical analysis and other non‑consumptive research

Prohibited

Redistributing the full texts in a form that is directly readable by humans (e.g. posting the articles as HTML or Markdown).
Publicly transmitting, broadcasting or otherwise making the original or modified texts/images available for human consumption.
Quoting or embedding the original works in downstream outputs in a way that allows them to be reconstructed or identified, unless the quotation satisfies the legal requirements of fair quotation.

Important: These restrictions narrow the scope of the Creative Commons BY 4.0 licence. By downloading or using MOMIJI you agree to the additional terms above.

Content Warning

Although an NSFW filter was applied, some links or text samples may still be disturbing. The dataset is intended for scientific or safety analyses by trained researchers.

Disclaimer

MOMIJI does NOT distribute image binaries—only links and metadata. We are not responsible for content accessible via those links. Filtering was performed automatically due to the dataset’s scale.

License Information

The metadata in this repository (YAML header, statistics tables and documentation) is licensed under CC-BY-4.0. The underlying web page texts and images remain subject to their respective copyright holders. Use beyond information‑analysis may require separate permission from the rights holders.

Acknowledgements

This model is based on results obtained from a project, JPNP20017, subsidized by the New Energy and Industrial Technology Development Organization (NEDO).