What to know before merging PDFs
Key points
- Merge in the order the recipient asks for
- Unlock password-protected PDFs first
- If it's too big, shrink photos first
More and more often you are asked to send several documents as a single PDF. Merging itself is easy, but knowing a few things in advance saves you from redoing the work.
1. Decide the order first
Many submissions specify an order, for example "application form, then references, then certificates". Following it makes life easier for whoever reviews your file. In merge PDF files, the list order is the page order, and the ↑ button changes it.
2. Password-protected PDFs
Some PDFs from banks or government offices ask for a password when opened. A program that doesn't know the password can't read the content, so it can't merge it. Open the file in a PDF viewer with the password, then use the print menu's "Save as PDF" to make an unlocked copy. Check first that the sender's policy allows this.
3. Why the file gets large
A merged PDF is roughly the sum of its parts. Scans and photo-heavy PDFs contain a large image on every page, so the size grows quickly. If there is an upload limit, try this:
- Resize photos before adding them. A width of 2000 pixels is plenty to read an A4 page.
- Scan at less than 300 dpi (around 200 dpi) for much smaller files.
- Scan documents that don't need color in black and white or greyscale.
4. Mixing landscape and portrait pages
Each PDF page has its own size and orientation, so mixing landscape and portrait documents keeps each one as it was. When adding photos with Fit to A4, landscape photos go onto landscape A4 pages.
5. Documents with personal information
Certificates and bank statements contain things like ID or account numbers. With online tools, check whether files are uploaded to a server. Bakkumteo merges inside your browser and never sends files. If the recipient doesn't need certain details, covering them is a good habit.