Merging is one of the few PDF jobs that really is as simple as it looks: choose the files, put them in order, download one document. The part that decides whether the result is useful is not the software — it is the order and the few settings people skip.
This guide walks through a clean merge, the scanner trick for fronts and backs, and the checks worth doing before the original files leave your desk.
Step by step
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1
Upload your files
Drag in your PDFs and images, or click Choose files. Order matters — the files are joined in the sequence shown.
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2
Order the files
Drag the file thumbnails into the order you want, or use the A–Z / Z–A buttons. Mixed PDFs and images are fine — each image becomes a page. There is no limit on how many files you add.
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3
Preview and trim
Click a file to read it page by page. In that view “Select pages” keeps only the pages you tick, so one file can contribute part of itself.
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4
More options
Double sided printing, one page size for everything, a table of contents, how bookmarks are handled, the file name in the footer and flattened form fields all live behind “More options”.
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5
Run it and download
Press Merge PDF and the page shows progress while it works. When it finishes you get a download link — nothing is emailed and nothing is stored longer than it needs to be.
What merging actually does
The merge tool copies the pages of each source document into a new PDF. It does not flatten or re-render the pages, so text stays selectable, images keep their resolution, and links and form fields come through wherever the source format allows. Your originals are never modified.
That also means a merge cannot fix a bad source page. If a scan is crooked or a page is upside down, repair it before merging with Deskew or Organize PDF; merging only changes the order of the stack.
Order is the part people get wrong
Every file arrives as a card, and the cards — not the order you uploaded them in — decide the final page order. Drag them until the document reads the way a stranger would expect: cover, main document, appendices, then supporting evidence. Reordering after a merge means opening the result and undoing work, so spend the extra ten seconds here.
If one file should contribute only a few pages, open it in the preview and use “Select pages” instead of merging the whole thing and deleting pages afterwards.
Merge scans without shuffling the pages
A single-sided scanner fed a double-sided stack produces two files: all the fronts, then all the backs in reverse. Do not merge those files and hope. Use Alternate & Mix, point it at both files, step by two and reverse the second file, and it interleaves the scans back into reading order.
Once the order is right, a scan-heavy merge is usually large. The merge itself preserves every image exactly, so run the finished PDF through Compress PDF afterwards if it needs to fit an email or upload limit.
A five-minute check before you send it
Open the downloaded file and check three things: the first and last page, the page count against the sources, and any bookmarks or form fields you expected to keep. For a contract, also check that the signature page still sits with the clauses it belongs to — page order is the one thing a merge can silently ruin.
If the merge needs more than order changes, take the result into the PDF editor or read the merge walkthrough for the scanner and page-selection details.
Good habits for Merge PDF
- Page thumbnails are tap-friendly, so you can reorder and delete on a phone.
- Every tool works on a copy — your original file is never modified.
- Use Split by text when a document has no bookmarks to split on.
Common questions
Is this tool free?
Yes. Every tool on this site is free to use, with no sign-up, no watermark and no daily task limit.
Do I need to install anything?
No. The tools run in your browser and are processed by this server.
What happens to my files?
They are stored under an unguessable id and swept automatically after a couple of hours. Nothing is shared or indexed.
Does it work on a phone?
Yes. The page pickers and editors are built for touch, so dragging, rotating and selecting pages all work without a mouse.
What does Merge PDF do exactly?
Combine multiple PDFs and images into one document.
Does merging reduce PDF quality?
No. Pages are copied into a new document rather than re-rendered or screenshotted, so text stays selectable and image resolution is unchanged. Any size reduction comes from a separate compression step.
Can I merge only some pages from a file?
Yes. Open a file’s page view and select the pages to keep before merging. The unselected pages are left out of the new document, and the original file is not changed.
Are bookmarks and forms kept?
Bookmarks and form fields are carried where the source PDF allows it. Check the merged copy if they matter — complex outlines can need a quick pass in Create Bookmarks.