Sending several PDFs as one attachment or upload
A form allows one attachment, a portal takes one upload, or you simply do not want to attach eleven files to an email one by one. A ZIP solves that: it is one file that holds the others. What it does not do for PDFs is make them noticeably smaller, which is worth knowing before you count on it.
Updated
Which tool you need
Several PDFs for one upload box, one email or one shared folder
PDF to ZIP. Each file is packed unchanged, top of the list first, and the result gives the total size before and after.
The files are too large to send, together or apart
Compress PDF makes each PDF itself smaller, which a ZIP cannot. Compress first, then zip the compressed files if you still want one file.
The recipient wants one document, not a bundle of them
Merge PDF joins the files into a single PDF, pages in the order you choose.
The bundle has to be locked with a password
This ZIP has no password. Lock each PDF with Password Protect PDF before zipping, so the files stay locked inside it.
Why zipping a PDF saves so little
Inside a typical PDF, the page text and fonts are already squeezed with the same kind of compression a ZIP uses, and photos are usually stored as JPEG. Compressing compressed data again finds almost nothing left to remove, so a few percent is a good result and a ZIP can even come out a little larger than its contents.
That is why the result states both sizes and the change between them rather than promising a saving. If the size is the problem, the pictures and fonts inside each PDF are where the space is, and only a tool that rewrites the PDF reaches them.
What ends up in the archive
Each PDF is stored byte for byte, so a signed or form-filled file comes out of the ZIP exactly as it went in. Files keep their own names and modification dates, and two files with the same name are told apart as report.pdf and report (2).pdf.
Once the archive is built, it is opened again on your device and every file in it is checked against the size it went in at before you can download it. The ZIP is named after the first file, with a count of the others when there are several.
What to know before you start
- Up to 200 files and 512 MB in one ZIP on a computer, 100 MB on a phone, since it is built in the browser's memory.
- The ZIP itself has no password or encryption.
- The PDFs are not compressed or changed in any way.