PDF Merger
Combine multiple PDF files into a single document — reorder them however you like, all processed locally in your browser.
How to Merge PDF Files
- Upload two or more PDF files (click or drag — the Merge button stays disabled until you have at least two).
- Each file shows a thumbnail of its first page — press and hold a file's grip handle and drag it to reorder, or use the up/down buttons.
- Click "Merge PDFs".
- Download the single combined PDF.
Frequently Asked Questions
Why is the Merge PDFs button disabled?
It only activates once you've added at least two PDF files — merging a single file wouldn't do anything, so the tool blocks the button and shows "Add at least one more PDF to merge" until a second file is added.
Does merging preserve bookmarks, links, or form fields inside each PDF?
Pages are copied over using pdf-lib's page-copying, which brings over each page's visual content faithfully, but complex features like cross-document bookmarks or interactive forms may not carry over perfectly since each source file's internal structure is being recombined into a new document.
In what order will my files be merged?
In the order shown in the file list, top to bottom — the order you upload them isn't final, so press and hold a file's grip handle and drag it into place, or use the up/down arrows, before clicking Merge.
Is there a limit to how many PDFs I can merge at once?
There's no hard-coded limit, but every page of every file is rendered as a thumbnail in your browser, so merging a very large number of large PDFs may slow down or strain your browser's memory since it's all happening on your device.
Can I merge PDFs that have different page sizes?
Yes — each source PDF's pages are copied as-is, so a merged file can freely mix page sizes (e.g. some A4, some Letter) without being forced onto a single uniform size.