A 200-page PDF is not always useful as a single file. You might need chapter three on its own. Or you want to email just pages 15 through 22. Or a professor submitted grades as one massive document and you need to separate it into individual student files. Splitting breaks a PDF into smaller pieces along boundaries you define. This tool runs locally in your browser — no upload, no server, no waiting in a queue.

When to use this tool

Splitting solves a different problem than extracting. Extraction pulls selected pages into one new file. Splitting divides the entire document (or a portion of it) into multiple output files at once. Reach for the split tool when:

• Breaking a document into chapters. A textbook, manual, or report with a clear section structure is easier to navigate and share when each chapter is its own file.
• Distributing sections to different people. A combined contract might contain exhibits A through F, each destined for a different department. Split once, distribute the pieces.
• Reducing file size for email. Email attachment limits (typically 25 MB) can block large PDFs. Splitting a 40 MB file into two halves lets you send it across two messages.
• Preparing individual records. Batch-generated documents — invoices, certificates, pay stubs — often arrive as one PDF with a record per page. Burst mode creates one file per page instantly.
• Isolating problematic pages. If a particular page causes rendering issues in a viewer, splitting it out helps you diagnose whether the problem is the page content or the document structure.

How splitting a PDF works

Splitting is conceptually the inverse of merging, but the internal mechanics are more nuanced than simply cutting a file at a byte offset.

A PDF document is an object graph. The document catalog sits at the root and references a page tree, which branches into individual page objects. Each page object points to resources it needs — font objects, image XObjects, color space definitions, and a content stream holding the drawing instructions. Many of these resources are shared. Ten pages that use the same font all point to a single font object in the file.

When the tool splits a document, it creates a new PDF for each output segment. For each segment, it:

1. Identifies the required pages. Based on your specified ranges, bookmark positions, or burst-mode logic, the tool determines which page objects belong in each output.
2. Copies page objects and their dependency trees. Each page is not just a flat block of data. A page references fonts, which reference encoding tables. Images reference color spaces. Annotations reference destinations. The tool walks each page's reference tree and copies every object it depends on into the new document.
3. Rebuilds the page tree. The new document gets its own page tree containing only the copied pages, numbered starting from 1.
4. Writes new cross-reference tables. Each output file is a self-contained, valid PDF with its own cross-reference structure mapping objects to byte positions.

This copy-and-rebuild process is why split files can be surprisingly large. If the original document embeds a 2 MB font that appears on every page, each split output that includes at least one page using that font will contain its own 2 MB copy. The original file stored it once; the splits each store it independently. This is unavoidable — a valid PDF must contain all resources its pages reference.

The split modes work as follows:

• By page range. You specify ranges like "1-5, 6-10, 11-20" and get three files. Ranges can overlap if you want certain pages to appear in multiple outputs.
• Burst mode. Every page becomes its own file. A 50-page document produces 50 single-page PDFs. Files are typically named with a page number suffix.
• By bookmarks. The tool reads the document's outline (the bookmark tree visible in the sidebar of most PDF viewers). Each top-level bookmark defines a split point. A document with five bookmarks becomes five files, each starting at its respective bookmark's target page and ending just before the next bookmark.

Common issues

Split files are larger than expected. As explained above, shared resources get duplicated across outputs. This is especially noticeable with documents that embed large fonts (CJK fonts can be 10 MB or more) or high-resolution background images on every page. If output size matters, run each file through Compress PDF afterward.

Cross-page links break. A table of contents on page 1 that links to chapter headings throughout the document will only work for headings that land in the same output file. Links to pages in other split files become dead references. There is no way to automatically convert internal links into cross-file links — the PDF specification does not support that. If you need working navigation, consider keeping the table of contents page in every output or distributing the full document alongside the splits.

Form field calculations stop working. PDF forms can contain JavaScript or calculation order entries that reference fields on other pages. If a summary field on one page sums values entered on pages scattered across multiple splits, the calculation will fail in any output missing the source fields. For forms with cross-page logic, consider flattening the form (which locks in current values as static content) before splitting.

Bookmark-based splitting produces unexpected results. This mode depends entirely on the quality of the document's bookmark tree. If bookmarks are nested, only top-level entries are used as split points by default. If bookmarks point to locations within a page rather than the start of a page, the split happens at the page containing that location. Documents without bookmarks cannot be split in this mode at all.

Annotations and comments. Sticky notes, highlights, and text annotations attached to specific pages travel with those pages into the split output. Annotations are page-level objects, so they do not get lost.

What to expect from our tool

Open the tool and load your PDF. The page count and a thumbnail preview help you decide where to split. Choose your mode — page ranges, burst, or bookmarks — and configure accordingly. Click split, and the tool generates your output files. If there are multiple outputs, they download as individual PDFs (or as a zip archive for burst mode with many files).

Processing speed depends on the document's complexity and size. A 20-page text document splits in well under a second. A 500-page image-heavy report takes a few seconds. Everything happens locally on your device.

The output files are complete, standalone PDFs. They open in any PDF viewer without requiring the original document. Page numbering restarts from 1 in each output. Metadata from the original (author, creation date, title) is not carried over to the splits — each output starts with a clean metadata slate.