Merge PDF Files Online

Merging PDFs combines several files into one clean document in the order you choose. It's one of the most common document tasks: stitching a signed contract onto its cover letter, combining scanned receipts for an expense report, or assembling chapters into a single deliverable. Instead of sending five attachments, you send one.

File Converts merges your files in your browser — they're never uploaded to a server. That keeps confidential paperwork private, removes any upload wait, and means there's no cap on how many files you combine or how large they are. Just add your PDFs, drag them into the right order, and download the combined file instantly.

Because the merge happens on your device, it's also fast: there's no round-trip to a server and back, so even a large stack of documents combines in moments. Page order is preserved exactly as you arrange it, and the original files are left untouched.

Merging pairs naturally with the rest of the PDF toolkit. Split a PDF first to pull out just the pages you need, then merge them with another document; add page numbers to the combined file; or run Compress PDF afterward if the merged result is large. Everything runs locally, so your documents never leave your computer at any step.

Best for

• Combining scanned pages, receipts, or signed forms into one file
• Assembling chapters or reports into a single document
• Merging a cover letter and portfolio before an application

Put the files in the right order before you merge

Once two or more PDFs are in the list, each one gets small up and down arrows. The merged document follows the list from top to bottom, so the first file's pages come first, then the second file's, and so on. Files you add later go to the bottom of the list, which makes it easy to build a packet in order: cover letter, then CV, then certificates.

The arrows move whole documents, not individual pages. If page 3 of one file needs to sit between two pages of another, merge first and then rearrange the combined file in Organize PDF. One more quirk: the list ignores a file with the same name and size as one already in it, so you cannot add the same PDF twice. To repeat something like a cover sheet, save a copy under a different name and add that.

What the merged file keeps, and what it leaves behind

Pages are copied across as they are. Text stays selectable, images are not re-compressed, and each page keeps its own size and orientation, so merging an A4 file with a US Letter file gives you a document with both page sizes in it.

Things that belong to a whole document rather than to its pages do not carry over. Bookmarks (the outline in a viewer's sidebar) and each source file's title and author are not copied, and the merged file starts with blank document properties. If the result needs a title, set one afterwards in PDF Metadata. Fillable form fields may also stop working once they are moved into a new document, so fill in any forms before merging, and flatten them in Fill PDF if the values must stay put.

Merging scans and photos with your PDFs

The converter takes one kind of file at a time. If you drop photos and PDFs in together, it says the selection is mixed and will not merge. Turn the photos into a PDF first with JPG to PDF or Images to PDF, then merge that PDF with the others.

Merging does not change what is on a page, so a scanned page is still a picture of text afterwards. To make the whole packet searchable at once, run the merged file through OCR PDF. That is one pass instead of one per source file.

How large a merge can get

Each file can be up to 50 MB. A bigger file is turned away when you add it, with a notice naming it, and the rest of your list is unaffected. The number of files has no fixed limit, but every file is held in memory while the merged document is built, so on a phone or an older laptop a very large stack is where you will run out of room first.

Because nothing is re-encoded, the merged file is roughly the combined size of what went in. If it is too big to email, there are two ways to shrink it. Split PDF sends fewer pages and keeps the text intact. Compress PDF shrinks scans a lot, but it turns every page into an image, so text stops being selectable.

What to do when the merge won't run

If the Convert button is greyed out and the tool asks you to add a second file, there is only one PDF in the list. A merge needs at least two.

If the merge stops with an error saying a document is encrypted, one of the files is protected. This includes PDFs that open without a password but carry restrictions, which bank statements and generated reports often do. The merge engine will not read any encrypted file. Remove the protection with Unlock PDF, which needs the file's password, then merge the unlocked copy. A file that is damaged or is not really a PDF fails with its own error. Opening it in a PDF viewer and saving or printing it to a new PDF usually produces a copy that merges. Files are recognised by the .pdf extension, so a PDF that has lost its extension needs renaming before it will appear as a PDF in the list.

Merging on your own device

The merge runs in your browser, the result downloads as merged-2.pdf, merged-3.pdf and so on (named for the number of files), and the upload counter stays at zero. Everything the merge needs comes with the page, so once the page has loaded it works with the network switched off.

What this tool does

How to convert Multiple PDFs → One PDF

Frequently asked questions

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