ipynb.app is a free online tool designed for converting Jupyter Notebook files (with the .ipynb extension) into various other formats. Its primary function is to transform interactive notebook files into static, shareable documents such as PDF, Word (DOCX), HTML, and image formats like PNG and JPG. The service is entirely web-based, requiring no software installation, user registration, or account creation to use. Key features of ipynb.app include support for unlimited file conversions with no file size restrictions, along with the ability to process bulk files. The tool is optimized for speed, converting files in seconds even for larger notebooks, and operates securely by processing files and automatically deleting them after conversion. Users also have the option to manually delete their files at any time. In addition to its primary conversion direction, the tool offers reverse functionality, such as converting PDF files back to the IPYNB format. Typical use cases involve data scientists, researchers, and educators who need to share their Jupyter Notebook work with audiences that do not have Python or Jupyter installed. The workflow is straightforward: a user uploads an .ipynb file by browsing or dragging it into the interface, selects the desired output format, and receives a polished, converted document. This process enables users to present code and results in universally accessible formats for reports, publication, or presentations without any technical setup or account management.