Merge PDF files
Combine several PDFs into one document, in the order you choose. Everything runs in this browser tab, so your contracts, scans and payslips are never uploaded.
- No upload
- No sign-up or watermark
- Page ranges & bookmarks
Combine multiple PDFs into one, in three moves
Add the files
Drop PDFs on the orange panel or tap it to choose. Add JPG or PNG scans too; each becomes a page.
Put them in order
Drag the grips, use the arrows, or sort A–Z. Type a range such as
2-5under a file to take only those pages, and turn a sideways file with ↻.Merge and save
Press Merge. The new PDF is built on your device, usually in a second or two, and saved to your downloads.
Private by design
A PDF merger with no upload
Most online PDF combiners send your files to a server, merge them there and send the result back. That round trip is why they ask you to wait, cap free use, and publish deletion policies.
PDFCombiner skips it. The page you loaded contains the whole merger: Mozilla’s pdf.js reads each file to draw the thumbnails, and pdf-lib copies the pages into a new document. Both run as JavaScript on your phone or computer. There is no file endpoint on our server to receive a PDF even if we wanted one.
You can check this yourself: open your browser’s developer tools, switch to the Network tab and merge something. You will see no request carrying your file. Or load this page, go offline, and merge anyway.
The one optional exception is clearly labelled: “Suggest an order” sends file names and a short snippet of page-1 text (never the file) to an AI model to propose an order. You don’t have to use it.
Honest limits
| Situation | What happens here |
|---|---|
| Ordinary PDFs | Pages are copied as-is: text stays selectable, links on the page keep working, images are not re-compressed. |
| Password to open | You type the password; it is used only in this tab. The output can't carry the old encryption, so those pages are re-drawn as images (about 144 dpi) and their text is no longer selectable. |
| Owner password only (no-edit / no-print flags) | Opens without asking, but is handled the same way as above: pages become images. We don't strip protection and hand back an editable copy. |
| Very large jobs | Everything is held in this tab's memory. A laptop copes with a few hundred MB; phones and tablets top out sooner. If a tab crashes, merge in batches and then merge the results. |
| Fillable forms | Field appearance is kept, but fields may stop being fillable in the merged file. Fill and save forms first. |
| Digital signatures | Any change to a signed PDF breaks the signature's validation. Merge copies if you need the signed original intact. |
| Original bookmarks | Not carried over. The merger can add one bookmark per file instead. |
More page tools
Same rule for all of them: the file stays on your device.
- Split PDFCut by ranges, every N pages, or extract pages.
- Organize pagesDrag pages into order, insert another PDF, add blanks.
- Remove pagesDelete the pages you don’t need.
- Rotate PDFTurn sideways or upside-down pages, losslessly.
- JPG to PDFMerge photos and scans into one PDF.
- Add page numbersStamp page numbers on a merged file.
Questions
Is PDFCombiner really free?
Yes. There is no sign-up, no watermark, no daily limit and no paid tier. The work is done by your own device, so it costs us almost nothing to run.
Are my files uploaded anywhere?
No. The files are read by JavaScript inside this browser tab (pdf.js to show pages, pdf-lib to write the new file) and the merged PDF is saved straight from memory to your downloads. You can load the page, switch off Wi-Fi and it still merges.
How do I change the order of the files?
Drag a file by its grip or thumbnail, or use the up and down arrows. “Sort A–Z” sorts by file name using natural number order, so “scan 2” comes before “scan 10”. The top file becomes the first pages of the result.
Can I merge only some pages from each PDF?
Yes. Type pages into the box under each file, for example 1-3, 7, 10- (10- means page 10 to the end). Leave the box empty to include the whole file. To rearrange individual pages, use Organize pages.
Can I combine PDFs with JPG or PNG images?
Yes. Drop images in alongside PDFs and each becomes a page, sized to A4, Letter or the image’s own proportions. For a stack of photos only, the JPG to PDF tool has the same options.
What about password-protected PDFs?
You are asked for the password to open the file. Because the merged document cannot keep that file’s encryption, its pages are re-drawn as images: they look and print correctly, but their text is no longer searchable.
Is there a size limit?
There is no fixed cap; the limit is your device’s memory. Laptops handle a few hundred megabytes comfortably. On a phone, keep a single job under roughly 100 MB, or merge in batches.
Will the merged file be bigger than the originals?
It will usually be close to the sum of the inputs. Fonts and images embedded in each source file are kept once per source, so merging many files that use the same font can be a little larger than you might expect.
Why merged PDFs behave the way they do
A PDF isn’t a stack of pictures; each page is a small program of drawing instructions that points at shared fonts and images. Merging means copying those pages and everything they point at into a fresh file, then rebuilding the index that lets a viewer find page 212 without reading pages 1 to 211.
That is why pages keep sharp, selectable text after a proper merge, and why a password-locked file is different: its contents are encrypted, so they have to be decrypted and redrawn instead of copied.
Step through what happens inside a merge, or read how to combine PDFs with the tools already on a Mac, Windows PC or iPhone.