Merge PDF
Combine multiple PDFs into one file.
How to use Merge PDF
Drop two or more PDF files into the uploader, or click to select them.
Drag the files to set the order in which they will appear in the merged document.
Click Merge PDF and wait a moment while the files are combined in your browser.
Download the merged PDF.
When merging is the right move
Merging turns several PDFs into one file with one page sequence and one set of bookmarks. It is the right tool when the documents belong together as a single deliverable: a scanned contract plus its annexes, the invoices for one expense claim, chapters written by different people, or the supporting documents a visa or mortgage application insists on receiving as one attachment.
It is the wrong tool when you only want some pages from each source. Merging everything and then deleting what you did not want is slower and risks leaving something in. Pull the pages you need first, then merge what is left.
- One upload limit, many documents — the most common reason people merge at all.
- A single print job instead of five, in the page order you chose.
- Bookmarks and internal links from each source survive the merge.
What merging does to your file
Pages are copied object by object into the new document, not re-rendered. Text stays selectable and searchable, vector graphics stay vector, and images keep the exact compression they arrived with — a merge never re-encodes a JPEG inside a page, so it cannot introduce the soft, blocky artefacts a compression pass would.
The result is roughly the sum of the inputs, sometimes a little less: fonts and colour profiles shared by several documents are stored once rather than repeatedly. If the merged file lands above the limit you are up against, compress it afterwards instead of merging fewer pages.
Page order, and the mistakes that cost the most
Files merge in the order shown in the list — not the order you selected them in, and not alphabetical order. Drag to rearrange before you click Merge. Checking a list of six filenames takes seconds; checking a 200-page output afterwards does not.
Two things go wrong regularly. Scans that came out sideways stay sideways in the merged file, so rotate them first. And a password-protected source cannot be merged while it is locked: remove the password, then merge.
Why this runs in your browser
Every step runs inside your browser, using the WebAssembly and Canvas APIs your device already ships with. No file is uploaded, no copy is kept, and nothing sits in a queue on a server waiting to be deleted — which is also why the tool keeps working with the network disconnected.
For merging that matters more than usual, because the documents people merge are the sensitive ones: payslips, medical records, signed contracts, identity papers. Uploading those to a stranger's server to save two clicks is a bad trade, and it is one you do not have to make.
Frequently Asked Questions
Is there a limit on how many PDFs I can merge?
You can merge up to 20 PDF files at once, with a combined size of up to 100 MB. Because merging happens in your browser, very large files depend on your device's memory.
Are my PDF files uploaded to a server?
No. The merge is performed entirely in your browser. Your files never leave your device.
Will the merged PDF keep the original quality?
Yes. Pages are copied without re-compression, so text, images and formatting remain exactly as in the original files.
Does merging PDFs reduce the quality?
No. Pages are copied rather than re-rendered, so nothing is re-compressed. Text stays selectable, vector graphics stay sharp at any zoom, and embedded images keep their original encoding byte for byte.
Can I merge a password-protected PDF?
Not while it is protected. An encrypted PDF's pages cannot be read until it is unlocked, so remove the password first with the Unlock PDF tool and then merge. If you have the owner password but not the open password, you will need the open password from whoever created the file.
Will bookmarks, links and form fields survive?
Bookmarks and internal links are carried over and remapped to their new page numbers. Interactive form fields are preserved, but if two sources contain fields with the same name they will share a value in the merged file — rename them beforehand if that matters.
How do I merge PDFs in a specific order?
Drag the file cards in the list before merging; the output follows that order exactly. Naming your files 01-, 02-, 03- before adding them makes a long list much easier to verify at a glance.
Can I merge images and PDFs together?
Convert the images to PDF first with the JPG to PDF tool, then merge the results. That way you choose the page size and orientation for the image pages instead of leaving it to guesswork.
Why is my merged PDF so large?
Because it contains everything the sources did. Scans are the usual culprit — a 20-page colour scan is easily 30 MB on its own. Run the merged file through Compress PDF if you need to fit an upload limit.
Related tools
Keep reading
- What Happens to a File You Upload to a Free PDF Site
Free online tools pay for their servers somehow. What the terms usually permit, and why doing the work in the browser removes the question entirely.
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