Merge PDF files online

How to use PDF Merge

1. Click “Add PDF files” or drop your PDFs onto the page.
2. Drag the files (or use the arrow buttons) to set the order.
3. Press “Merge PDFs”, then download the combined file.

What merging PDFs actually does

A PDF is a container of pages. Merging copies the pages from several PDF files into one new document, in the order you choose. The text, fonts, images and layout of every page are carried over unchanged, so a merged file looks identical to the originals placed one after another.

People merge PDFs for everyday reasons: combining a scanned ID with a signed form for an application, joining chapters of a report written by different people, putting invoices for one month into a single file for accounting, or bundling a CV, cover letter and certificates into one attachment.

Tips for a clean merged document

A few habits make the result easier to read and share:

• Order matters. Put the files in reading order before you merge, using the arrows or by dragging them.
• Check page sizes. Mixing A4 and US Letter works, but pages keep their own size, so printing may scale them differently.
• Name the output clearly. The tool saves merged.pdf; rename it to something such as “2026-03-invoices.pdf” so you can find it later.
• Mind the size. Many email systems reject attachments over 20–25 MB. If your merged file is too big, compress the images inside the source PDFs first.

Why a browser-based merger is safer

Most online PDF merge sites upload your files to their servers, process them and send them back. That is a problem when the documents contain contracts, medical records, bank statements or identity documents, because you lose control over where the copies are stored and for how long.

This tool uses the pdf-lib JavaScript library inside your browser tab. The files are read into your device’s memory, combined there, and offered back as a download. You can verify this yourself: open your browser’s network inspector while merging and you will see no file data leaving the page. It also works with your connection switched off once the page has loaded.

Common problems and fixes

• “Could not read” error: the PDF is probably password-protected or damaged. Open it in a PDF viewer, remove the password (print or export to a new PDF) and try again.
• Bookmarks or form fields missing: merging copies page content. Interactive features such as bookmarks and some form fields may not be carried across.
• Very large files feel slow: merging happens on your device, so a phone with little free memory will be slower than a laptop. Merge in smaller batches if needed.

Why use this pdf merge tool

• 100% private. Files are merged on your device. Nothing is uploaded to a server.
• No limits or watermark. Merge as many files as your device can handle, with no logo added.
• Reorder freely. Rearrange or remove files before you merge.
• Works everywhere. Runs on phones, tablets and desktops, with no software to install.

Frequently asked questions

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