Merge PDF — combine & join PDF files free online
Combine several PDFs into one file in any order you like, with no page limit and no watermark. Merging runs in your browser, so documents stay private.
About the Merge PDF tool
Merging PDFs is one of those tasks that appears constantly and has no obvious home. A scanned contract arrives as one file and its signature page as another. An expense claim needs six receipts submitted as a single attachment. A report was written in sections by different people. Every one of these ends with someone needing one document where there are currently several, and neither Windows nor macOS offers an obvious way to do it.
The awkward part is that a PDF is not a text file you can concatenate. It is a structured document with an internal cross-reference table, embedded fonts, and objects that point at each other by number. Joining two of them properly means rebuilding that structure so every reference still resolves. This tool does that with pdf-lib, running as JavaScript in your browser, which is why it can handle the job without a server and without ever seeing your document.
Order is the thing to get right, and it is the thing most often got wrong. Files merge in the sequence they are listed, not alphabetically and not by the order you happened to select them in — so arrange them deliberately before merging. Rename files with a leading number if you assemble the same kind of bundle regularly; it makes the correct order obvious at a glance and saves re-doing the merge.
What comes out is a genuine single PDF, not an archive or a bundle. It opens in any reader, prints as one continuous document, and can be emailed as one attachment. Page numbers from the original files are not renumbered, since they are drawn onto the pages themselves rather than stored as a property — if continuous numbering matters, that needs to be handled before the merge, in whatever produced the pages.
How it works
Add your PDFs
Drop in two or more files. They are read from your device, and there is no cap on how many or how large.
Check the order
The list shows the exact sequence the pages will appear in. Rearrange it until it reads the way you want the document to.
Merge and download
One combined PDF is built and saved to your downloads. The source files are left exactly as they were.
Frequently asked questions
- Is there a limit on file size or page count?
- No imposed limit, because there is no server paying for the work. The real constraint is your own device: the documents are held in memory while they are combined, so merging a large number of scan-heavy files on a low-memory machine can slow down or stall the tab. If that happens, merge in two stages rather than all at once.
- Will the merged file have a watermark?
- No. Nothing is stamped onto the pages, no trailing advert page is appended, and there is no paid tier that removes a mark. The output is your pages in your chosen order and nothing else. The site is funded by advertising on the page rather than by degrading the file you came for.
- Are my documents uploaded to a server?
- No, and this is the main reason to use a browser-based merger. The files are parsed and rebuilt inside your own tab, so contracts, medical records, bank statements and anything else confidential never travel over the network and are never written to somebody else's disk. Going offline before merging is a quick way to prove it.
- Can I merge a password-protected PDF?
- Not while it is encrypted. A protected file cannot be read without its password, so remove the protection first in whichever reader you use to open it — usually by opening it with the password and re-saving a copy without one — and then merge that copy. Files that are merely restricted from printing or editing normally merge without trouble.
- Does merging reduce quality or increase file size?
- Quality is untouched: pages are copied across as they are, not re-rendered or re-compressed. The combined size is roughly the sum of the inputs, sometimes slightly less where two files embedded the same font and it only needs storing once. If the result is too large for an email limit, compress the images before building the PDF rather than after.
- Can I merge images and PDFs together?
- Not in a single step here. Convert the images to a PDF first with the Image to PDF tool, then merge that with your other documents. It is one extra step, but it lets you control page order and orientation for the images separately, which usually produces a tidier result than an automatic mixed merge.
- Do bookmarks, form fields and links survive?
- Page content, text and images come across faithfully. Interactive features are less certain — document-level bookmarks and form field data may not carry through a merge, since they live in structures that belong to the original document rather than to individual pages. If a form must stay fillable, check the merged file before relying on it.