NovaThis guide covers when merging is the right tool, how to get the page order right, and what we measured when we merged real files with NovaPDFTool, including how big the result was and how long it took.
When merging is the right move
Merging is common after scanning a document one sheet at a time, when several people each write a section of a report, or when a form and its supporting papers need to travel as one attachment instead of five.
One merged PDF has a single, fixed reading order. Five separate attachments don't: the recipient opens them in whatever order their email app lists them, which is rarely the order you meant.
How to merge PDF files, step by step
- Open the merge tool. Go to novapdftool.com/merge in any modern browser, on a computer or a phone.
- Add your PDFs. Drop the files onto the box, or click Browse files and select several at once. You can add more files later; they join the end of the list.
- Wait for the thumbnails. Every page of every file appears as its own thumbnail, labelled with the file name and page number.
- Set the page order. Drag a page to a new spot, or use the up and down arrow buttons under it. The number in the corner of each thumbnail is its position in the final file.
- Rotate or remove pages. Use the rotate button on a sideways page and the remove button on any page you don't want. Removing a page here never changes your original file.
- Click Merge files. The combined PDF downloads as merged.pdf. Rename it to something the recipient will recognise.
- Check the result. Open the merged file and scroll through every page before you send it, paying attention to the page order.
The Merge files button stays greyed out until there are at least two pages in the grid. That also means you can add a single multi-page PDF on its own just to reorder, rotate or drop some of its pages.
What we measured
How we tested: we ran the live NovaPDFTool code in Chrome 155 on a Windows laptop (Intel Core i5-12450H, 16 GB RAM) on 17 October 2026, using sample files we built for testing. Times are the middle of three runs. A phone or an older computer will take longer, so treat the times as a comparison between settings, not a promise. The files were a 10-page colour scan at 300 DPI (A4), a 20-page text report (US Letter) and a 2-page landscape table (A4).
| Files merged | Pages | Input total | Merged file | Reading pages | Merging |
|---|---|---|---|---|---|
| Scan + report + table | 32 | 18.47 MB | 18.47 MB | 2.6 s | 0.27 s |
| Report + table only | 22 | 37.0 KB | 37.5 KB | 1.0 s | 0.16 s |
Three things stand out:
- The merged file is the size of its parts. Pages are copied into the new file without re-encoding a single image, so there is no quality loss, and also no size saving.
- Most of the wait happens before you click. In the larger test, reading the files and drawing a thumbnail for each page took about ten times longer than the merge itself. More pages mean a longer wait for thumbnails.
- Page sizes survived untouched. The merged file still had A4 portrait, US Letter portrait and A4 landscape pages, each at its original size.
Getting the order right
Pages appear in the order the files were added, and files you add later go to the end. If you select several files at once, check the first thumbnails: your computer may hand them over in a different order from the one you clicked.
- Use the position number. The small number on each thumbnail is where that page will sit in the merged file. Read down the numbers once before you merge.
- Use the label. Each thumbnail is labelled with its file name and page number, such as "invoice.pdf · p2", which helps when two files look alike.
- Use the arrows for long moves. Dragging is quick for a small nudge. On a phone, or when a page has to travel a long way, the up and down arrows are more precise.
Because every page is in one grid, you aren't limited to whole files. Page 3 of the second file can go before page 1 of the first, which is handy for putting a signed cover sheet at the front of a report.
Mixed page sizes and orientations
A merge doesn't force pages onto one size. A portrait A4 letter can sit next to a landscape spreadsheet export, and each keeps its own dimensions. That is usually what you want, because resizing pages to match would shrink or distort their content.
If a page comes out sideways, rotate it in the grid before merging. Each click turns it 90 degrees clockwise on top of any rotation it already had, and the thumbnail shows the result.
What carries over, and what doesn't
- Carries over: everything you can see on each page: text, images, page size and orientation. Text that was selectable in the original stays selectable.
- Doesn't carry over: the bookmarks or outline panel of the original files. Fillable form fields and links that jump to another page may also stop working, so fill in and flatten forms before you merge them.
- Can't be opened: password-protected PDFs. Remove the password in the app that made the file first.
If the merged file is too big to send
Since merging adds sizes together, combining several scans can easily pass an email limit. Gmail, for example, caps attachments at 25 MB. You have two options:
- Make it smaller with Compress PDF. It suits scanned pages best; see our compression guide for measured results.
- Send it in parts with Split PDF, which can aim for a size per part.
If some of your pages are photos rather than PDFs, convert them first with Images to PDF, then add the result to the merge.