How to merge PDFs
- Add the files. Choose them or drag them onto the drop area. Each file shows a thumbnail of its first page, its size and its page count.
- Put them in order. Drag a file up or down the list, or use the arrow buttons. The top file comes first in the merged document.
- Choose pages (optional). Leave the Pages box blank to include the whole file, or type a list such as
1-3, 7, 10-. A reversed range like5-1adds those pages backwards. - Rotate a file (optional). Rotate turns every included page of that file by 90° each click. That is useful when one scan came out sideways.
- Merge. The result is built in a background worker and offered as a download named after the first file with
-mergedadded.
What the merged file keeps
Merging copies each page object, with its text, images, fonts, vector graphics, annotations and form fields, into a new document. Text stays selectable and searchable, and images are not re-compressed, so quality is identical to the originals. What does not carry over is document-level structure that cannot be combined: each source file's bookmarks (outline), its document title and other metadata, and document-level JavaScript. If you need a table of contents in the merged file, add it in your PDF editor afterwards, or put a contents page first.
Page sizes are kept as they are. If you merge an A4 file with a US Letter file, the result contains pages of both sizes, which every viewer handles. If a portal insists on uniform pages, convert the odd one out to images and back with JPG to PDF, choosing A4.
Common uses
Visa and immigration applications
Immigration portals often want one PDF per evidence category, such as identity, relationship or financial evidence, rather than dozens of single scans. Merge the scans for each category into one file, in a logical order, and check the result against the portal's per-file limit. ImmiAccount, for example, is commonly quoted as allowing 5 MB per attachment and refusing encrypted PDFs (we could not confirm this on the current Home Affairs page). If the merged file is over the limit, run it through Compress PDF.
Certified copies
When a document has been certified page by page, keep the certified pages together and in order, and do not crop or re-scan them. Merging does not alter the pages, so the certifier's stamp and signature stay exactly as scanned.
Reports and submissions
Combine a cover letter, the main document and appendices into one file for a single upload or email attachment. Use Add page numbers afterwards so references like "see page 14" work across the whole bundle.
Troubleshooting
- "Password-protected" message. The file is encrypted. If you know the password, remove it with Unlock first.
- A page appears blank in the result. Rare, and usually a damaged source file. Open the source in your browser's PDF viewer; if it also shows blank there, re-export or re-scan it.
- The merged file is huge. Merging adds file sizes together; it does not shrink anything. Compress afterwards.
- Very large jobs fail. Browsers limit how much memory one tab may use. Close other tabs, merge in two halves, then merge the halves.
On a phone or tablet
Merging works the same on a phone. Tap Choose PDFs and pick files from Files (iPhone) or your Downloads or Drive (Android); hold to select several. Reorder with the arrow buttons, which are easier than dragging on a small screen, then tap Merge. The merged file goes to your Downloads (Android) or opens in a preview you can save to Files (iPhone). Phones have less memory than computers, so for very large bundles merge in two halves.
Merging versus combining in a viewer
Some PDF viewers can "insert pages" from another file. The result is similar, but many save the change by appending to the original file, which keeps the old structure, and sometimes old content, inside it. Merging here always builds a fresh document from copies of the pages, which is cleaner and usually smaller.
Naming the merged file
The download is named after the first file with -merged added. Portals and recipients find a descriptive name helpful, so rename it before you send it, for example Smith-relationship-evidence.pdf.
Privacy: the file stays on your device
Online PDF services upload your document to their servers, process it there and keep it for a while. This tool does the work in your browser. The file is read into the page's memory, processed by open-source libraries (pdf-lib for editing and pdf.js for rendering) in a background worker, and the result is offered back as a download. Nothing is sent anywhere, there is no account, and closing the tab discards everything. You can check it: open your browser's developer tools, watch the Network tab while you run the tool, and you will see no upload. After the page has loaded once it also works offline.