Split Your PDF Into Parts Split PDF into parts.

The tool utilizes client-side JavaScript with React to handle PDF splitting, leveraging the `pdf-lib` library to interact with PDF documents. When a user selects a file, it is loaded into memory using the `arrayBuffer()` method and then passed to `PDFDocument.load()` from `pdf-lib`, which parses the PDF file and returns a document object. This object provides access to the PDF's page count, allowing the tool to determine the number of pages to split. The `buildGroups` function is responsible for constructing index groups based on the chosen mode, using algorithms such as range parsing for custom ranges or simple arithmetic for splitting at a specific page number or every N pages.

The `parseRangeGroups` function plays a crucial role in handling custom page ranges by tokenizing the input string, identifying individual pages and ranges, and converting them into arrays of 0-based indices. These indices are then used to create new PDF documents using `PDFDocument.create()` and `copyPages()`, which copies the specified pages from the original document into the new ones. The resulting PDFs are saved as blobs and their URLs created using `URL.createObjectURL()`, allowing users to download the split files. Throughout this process, React's memoization capabilities, such as `useCallback`, help optimize performance by minimizing unnecessary computations and re-renders.

The tool's UI is built with responsiveness in mind, ensuring that it adapts to different screen sizes and devices. Error handling is also implemented to catch and display any issues that may occur during file loading or PDF processing, providing users with informative error messages instead of cryptic errors. By operating entirely client-side and using `pdf-lib` for PDF manipulation, the tool ensures that sensitive documents are processed locally without being uploaded to servers, addressing data privacy concerns. This approach enables secure and efficient PDF splitting directly in the browser.