How to Merge PDF Files on iPhone

Scanned pages, signed forms, a couple of receipts you need to send as one attachment — combining several separate PDFs into a single file is a job that comes up constantly on iPhone, and there’s no built-in way to do it. Grabio’s “Merge PDFs” option gets you there in a few taps from the share sheet, free and with no account.

Why merging PDFs on iPhone is harder than it should be

The Files app lets you rename a PDF or move it, but it has no merge action. Mail and Messages only let you attach files one at a time, so multi-page scans and multi-document forms stay separate unless you own a dedicated PDF app or a Mac. Most people end up emailing several PDFs to themselves and merging them later on a laptop, which defeats the point of doing everything on the phone.

How to merge PDF files on iPhone with Grabio

1. Add Grabio to your iPhone once — it’s a free Apple Shortcut. Get the free Shortcut here and it’s ready in a few seconds.
2. Open one of your PDFs in the Files app or Mail and tap the Share button.
3. Scroll down the share sheet and tap Grabio.
4. Grabio detects the PDF and shows the PDF menu — tap Merge PDFs.
5. Read the short alert Grabio shows you, then tap through — it opens PDF24 in your browser with your file already picked.
6. On PDF24, tap Choose Files to add the rest of your PDFs, then tap Merge. Your combined PDF downloads straight to your iPhone.

Is it private and free on iPhone?

Be upfront about this one: unlike Grabio’s other tools, merging PDFs doesn’t happen on-device. No action in Apple’s Shortcuts app can actually combine PDF files locally, so for this one job Grabio hands you off to PDF24, a free, ad-light, well-known PDF tool, with your file already selected. It’s still free with no account, no login, and no upload limit forced on you by Grabio itself — but the merge step runs on PDF24’s site, not on your phone.

Merge PDFs on iPhone: FAQ

Why does this open a website instead of merging on my phone directly?

Because no Shortcuts action can merge PDF files on-device — Apple simply doesn’t provide one. Grabio’s other tools (cropping, converting, resizing) run entirely on your iPhone, but merging is the one job that has to happen on a website. PDF24 does it for free in a couple of taps.

Is PDF24 safe to use?

PDF24 (tools.pdf24.org) is a well-known, widely used free PDF tool with light advertising and no login requirement. Grabio only hands off to it for the actions iOS can’t do locally, and no file ever passes through Grabio’s own servers during the merge.

How many PDFs can I merge at once?

PDF24 lets you add as many files as you need through its Choose Files picker — there’s no cap set by Grabio. Add each PDF you want in the merge, then tap Merge once they’re all listed.

Related on iPhone: scan a document or receipt to PDF, compress a PDF, or PDF & Document Tools.