How merging works
When you click Merge, the tool reads each PDF, copies every page into a new document in the order you chose, and saves the result as one file called merged.pdf. Pages are copied as they are: text stays selectable and searchable, page sizes and orientation are kept, and images are not recompressed, so the quality does not change.
All of this happens in your browser using JavaScript. Your files are not sent to a server, which is why the tool works with sensitive documents such as contracts, bank statements, payslips and ID scans.
“Merge PDF” and “combine PDF” mean the same thing: several PDF files go in, one PDF comes out. Some apps call it “join” or “bind”. The steps are always the same: add the files, put them in order, and save.
How to combine PDF files with this tool
- Click Choose PDF files, or drop them on the box. You can add more files later.
- Each file shows its size and page count, plus a running total of pages.
- Use the up and down arrows to put the files in order, and the bin icon to remove one.
- Click Merge, then Download merged PDF.
Example: a job application needs a 2-page CV, a 1-page cover letter and a 6-page set of certificates as one upload. Add all three, move the cover letter to the top, and merge. The result is a single 9-page PDF, with the cover letter on page 1, the CV on pages 2–3 and the certificates on pages 4–9.
What is kept and what is lost when you merge
Merging copies pages, not whole documents. Anything that lives on a page travels with it. Anything that belongs to the document as a whole stays behind. Here is what that means for this tool:
| Part of the PDF | After merging |
|---|---|
| Text, fonts, images, vector drawings | Kept exactly |
| Page size and orientation | Kept, so A4 and Letter pages can sit in one file |
| Comments, highlights and other annotations | Kept, because they are attached to their page |
| Links to websites | Kept and still clickable |
| Links that jump to another page in the same file | May stop working, because the target page has moved into a new document |
| Bookmarks (the outline in the sidebar) | Not copied; the merged file has no bookmarks |
| Fillable form fields | May still show, but may no longer work as a fillable form; fill and save the form first |
| Document title, author and other properties | Not copied from the originals |
| A password on the merged file | Not added; use Protect PDF afterwards if you need one |
If you rely on bookmarks or a clickable table of contents, add them again in a desktop PDF editor after merging. For forms, the safest order is: fill each form, save it, then merge the saved copies.
Tips for a clean merged PDF
- Name files in order first. If your files are called
01-cover.pdf,02-report.pdfand so on, select them all at once and they will usually arrive in the right order. - Check page orientation. If one document has sideways pages, fix them with Rotate PDF before or after merging.
- Reorder single pages. The arrows here move whole files. To shuffle individual pages after merging, use Organize PDF.
- Keep the file size down. Merging scanned documents can create a large file. Run the result through Compress PDF if you need to email it or upload it to a portal with a size limit.
- Need only some pages? Use Split PDF to extract the pages you need, then merge those.
Will the merged PDF be bigger?
Expect the merged file to be close to the total of the files you put in. Three PDFs of 1.2 MB, 800 KB and 3 MB make a file of roughly 5 MB. It can come out a little smaller, because the tool packs the file structure more tightly when it saves, but it never shrinks the images. If each original embeds the same font or logo, the merged file stores a copy from each one. The Recommended level of Compress PDF finds those byte-for-byte duplicates and keeps a single copy, without touching quality.
How to merge PDFs with images
This tool only accepts PDF files; photos and scans saved as JPG or PNG are skipped with a warning. Convert them first:
- Turn the images into a PDF with JPG to PDF. You can put several photos into one PDF there.
- Come back here and merge that PDF with your other documents.
This is the usual route for a scanned ID card plus a typed application form: the photo becomes a one-page PDF, then both files are combined.
How to merge PDFs on Windows
Windows 10 and 11 can open PDFs in Microsoft Edge, but neither has a built-in way to combine them. Your honest options are:
- A browser tool, like this page, in Edge, Chrome or Firefox. Nothing to install, and the files stay on your PC.
- Adobe Acrobat. Combining files is part of Acrobat’s paid plans; Adobe also offers some free online tools, which upload your files to its servers.
- Other desktop PDF editors, free or paid. Check where they send your files and what they add, such as watermarks.
Printing to “Microsoft Print to PDF” does not help here: it prints one document at a time, so you still end up with separate files.
How to merge PDFs on a Mac with Preview
Macs have a merge tool built in:
- Open the first PDF in Preview and choose View > Thumbnails to show the page sidebar.
- Drag the second PDF from Finder onto the sidebar, at the point where its pages should go.
- Drag thumbnails up or down to change the order.
- Choose File > Export as PDF to save the combined file.
Preview saves changes to the open file automatically, so choose File > Duplicate first if you want to keep the original untouched. Finder’s Quick Actions > Create PDF can also combine a selection of files.
Merging on a phone
On iPhone, tap Choose PDF files, then Browse to pick files from the Files app or iCloud Drive. On Android, pick files from Downloads or Google Drive. The merged file saves to your Downloads folder, where you can share it to email or WhatsApp. Our step-by-step guide on how to merge PDF files covers every device, including Apple’s own apps on iPhone and iPad.
Common uses
| Task | What to merge |
|---|---|
| Job application | CV, cover letter and certificates in one file |
| Visa or university application | Passport scan, bank statements and transcripts |
| Accounts | Monthly invoices or statements into one yearly file |
| Study notes | Lecture slides from several weeks |
| Contracts | Signed pages and annexes into a single agreement |
Why some PDFs won’t merge
A small number of PDFs cannot be combined:
- Password-protected files. If a PDF needs a password to open, the tool marks it and links to Unlock PDF. Unlock it with the password, then merge.
- Damaged files. A file that was only partly downloaded may not open. Download it again and retry.
- Not really a PDF. Some files ending in .pdf are actually images or web pages. Open the file to check, or convert images with JPG to PDF.
The tool marks any file it cannot read and merges only the files that opened, so you can remove the problem file and carry on.