iPhone 合并 PDF：Safari 工具 / iPhone PDF Merge: Safari Tool

An iPhone PDF merge sounds like a job for an app, and for years it was. It no longer has to be. Most people looking up how to merge PDFs on iPhone have three photos of a signed contract, ten minutes, and no wish to hand a scanned passport to a server they have never heard of. That last part deserves some weight, because uploading is the default behaviour of nearly every free PDF website: the file goes up, gets merged, comes back down, and sits on someone else's disk for as long as their retention policy allows.

Two routes skip the upload entirely. iOS merges PDFs on its own through the Files app, and Safari can run the merge inside a tab using WebAssembly, the same mechanism desktop browsers rely on. Both keep the document on the phone, so privacy is not what separates them. What separates them is how each one behaves once the job stops being trivial.

Method 1: merge PDFs with the Files app on iPhone

Put the PDFs into one folder, tap Select, tap each file, then use the share menu and choose Create PDF. The combined document appears in the same folder. No account, no upload, nothing to pay.

Two limits show up fast. The result stops at roughly 15 pages, and the order is locked the moment you select the files, so rearranging afterwards is not possible. iOS also sorts filenames as text rather than as numbers, which puts page-2.pdf after page-19.pdf unless you renamed things first. Renaming costs half a minute and saves a complete redo.

For two or three short documents this is still the quickest option on the phone. Past that point it stops saving you time.

Method 2: Safari as your iPhone PDF merge tool

Open Safari, load a tool that processes files locally, add your PDFs, put them in order, and save the result back to Files. PDFMergeNext runs the merge through WebAssembly inside the tab, so the document never leaves the iPhone, and the tab keeps working after you lose signal.

This is the route to take past 15 pages, when the sequence needs fixing, or when you only want part of a file. Page selection with a syntax like 1-3,5 lets you drop a cover sheet and the blank scan at the end without a second pass. If you are merging phone snapshots rather than proper scans, check how much quality a compressed PDF merge costs before you start, because the merge is not what degrades the image.

The screen is small, so judge a tool by whether its controls were laid out for a thumb. A drag handle the width of a finger beats a tiny arrow you have to hit twice.

I stopped recommending App Store merge utilities for one-off jobs. Most of them give you two or three files on the free tier and then put a weekly subscription in front of you, which is a bad trade for something iOS already does.

iPhone PDF merge options, compared

Free and harmless are not the same thing. The upload row costs no money and leaves a copy of your document somewhere else, which matters when the file is a lease, a medical form, or anything carrying an ID number.

Three checks before the file goes anywhere

• Count the pages. Open the merged file and compare the total against what you expected. A merge that quietly drops two pages tends to surface three days later, in front of whoever needed it.
• Check the joins instead of the filenames. Scroll to where one source document ends and the next begins, and confirm the transition reads correctly.
• Compare file size. Output much larger than the sum of the inputs means something re-encoded the pages. Output much smaller means images were compressed again. Neither is automatically wrong, but you want to know which one happened.

An iPhone PDF merge works well enough these days that the choice comes down to two numbers: how many pages, and how much the order matters. Everything past that is preference.