Merge and split PDF files

How it works

The page uses pdf-lib, an open-source PDF library that runs inside your browser. When you add a file, your browser reads it from your disk into memory and counts its pages. Nothing is sent to a server.

• Merge makes a new, empty PDF and copies every page of each file into it, file by file, in the order shown in the list.
• Extract pages copies only the pages you list, in the order you write them, into one new PDF.
• Split copies the pages into a new PDF for every page, or for every N pages. If you get more than one file, you can download them one by one or all together in a ZIP file.

Pages are copied, not re-drawn: their text, images and fonts are carried over byte for byte, so quality stays exactly the same and text stays selectable.

Writing page ranges

• 5: page 5 only.
• 1-3: pages 1, 2 and 3.
• 8-: page 8 to the last page. -3: page 1 to page 3.
• Separate parts with commas: 1-3,5,8-. Pages come out in the order you write them, so 3,1 puts page 3 first. A page listed twice appears twice.

Worked example

You have report.pdf with 10 pages.

• Extract 1-3,5,8-: you get one PDF with 7 pages (pages 1, 2, 3, 5, 8, 9 and 10 of the original), named report-pages-1-3_5_8-10.pdf.
• A new PDF every 4 pages: 10 ÷ 4 = 2 full files and 2 pages left over, so 3 files: report-pages-1-4.pdf, report-pages-5-8.pdf and report-pages-9-10.pdf.
• Every page separately: 10 files, report-page-1.pdf to report-page-10.pdf, plus report-split.zip holding all of them.
• Merge it with a 3-page cover letter placed first: one 13-page PDF with the letter's pages first, then the report's 10 pages.

Limits

• Encrypted PDFs (with an open password or with editing restrictions) cannot be merged or split here. You will see a message naming the file. Open it in a PDF reader that knows the password and save or print an unprotected copy first.
• Bookmarks (the outline) are not kept. Interactive form fields may stop being fillable, and links that jump to another page of the same document may stop working. Links to websites keep working.
• Digital signatures do not carry over, because the result is a new document.
• The new file's document properties name pdf-lib as the program that made it. The original title and author are not copied.
• Size: there is no fixed limit, but the whole file is held in your device's memory. Files of tens of megabytes are fine on most devices. Several hundred megabytes may fail on a phone; the page warns you above 300 MB in total.

FAQ

Are my files uploaded?

No. Your files are processed in your browser and never uploaded. You can disconnect from the internet after the page loads and it still works.

Does merging or splitting reduce quality?

No. Pages are copied as they are, without compressing or re-rendering anything, so text, images and scans look exactly the same.

Why is a split file almost as big as the original?

Each new file must include the fonts and images its pages use. If every page uses the same large font or a full-page scan, each part carries its own copy. To make a PDF smaller you need a compression tool, which this is not.

Can I merge a password-protected PDF?

Not here. The tool cannot read encrypted files, and it will tell you which file is the problem instead of failing silently.

Can I reorder single pages, not just files?

Yes, with extract: write the pages in the order you want, for example 2,1,3- to swap the first two pages.

How many files can I merge?

As many as your device's memory allows. Dozens of ordinary documents are no problem.

Credits

PDF handling uses pdf-lib by Andrew Dillon (MIT licence), bundled with this site with its licence notice. The ZIP file is written by a small routine of our own.