How to merge PDF files on your phone

The short answer

You can merge PDFs on a phone in under a minute by using a browser tool: open Merge PDF in Chrome or Safari, tap to add your files, arrange them, and download one combined PDF. It works the same on Android and iPhone, and the files are processed on your phone instead of being uploaded.

Before you start

Collect the PDFs in one place first, because picking from several folders is slower. On Android, files from WhatsApp, email and downloads are usually in the Downloads or Documents folder. On iPhone, they are in the Files app under On My iPhone, iCloud Drive or Downloads. If your documents are photos instead of PDFs, turn them into a PDF first with JPG to PDF, then merge.

Merge PDFs on Android

On Android, use Chrome (or any modern browser) and follow these steps:

1. Open toolbyte.app/merge-pdf in Chrome.
2. Tap the add files area. Android opens its file picker.
3. Select two or more PDFs. You can tick several at once, or add them in separate rounds.
4. Drag the files into the order you want. The first file becomes the first pages of the result.
5. Tap Merge. The combined PDF downloads to your Downloads folder.
6. Tap the download notification to open the file, or find it in the Files app.

If the picker only shows images, switch to the Documents or Downloads view from the menu at the top left of the picker.

Merge PDFs on iPhone

On iPhone, use Safari or Chrome and the Files app:

1. Open toolbyte.app/merge-pdf in Safari.
2. Tap the add files area and choose Browse to open the Files app.
3. Pick your PDFs from iCloud Drive, On My iPhone or another location, then tap Open. Repeat if the files are in different folders.
4. Arrange the order and tap Merge.
5. When the download finishes, tap the download icon in Safari's address bar and open the file. It is stored in the Files app under Downloads.
6. To share it, open the PDF and use the share button to send it by email, WhatsApp or AirDrop.

Get the order right

The order you see before merging is the order of the final document. Check it before you tap Merge, because fixing it afterwards means starting again. A few habits help:

• Name files with numbers (01, 02, 03) before you add them, so they are easy to recognise in the list.
• Put cover pages or forms first and supporting documents after.
• If one file has pages in the wrong order, fix it first with Organize PDF, which lets you reorder or remove pages inside a file.
• If a scanned page is sideways, use Rotate PDF first.

Size limits and slow phones

There is no fixed server limit, because your phone does the work. As a rough guide, a combined size of up to about 100 MB works well on most recent phones, and older phones may struggle earlier. If the page slows down or stops, merge in two smaller batches and then merge the two results.

Keep the screen on and stay on the tab while the merge runs. Phone browsers may pause background tabs to save memory, which can interrupt a long job.

Common problems

The merge button does nothing. You need at least two files in the list. Add another PDF.

A file is rejected. Password-protected PDFs cannot be merged while they are locked. Remove the password in the app that created it, then add the file again.

The result is huge. Merging does not compress anything, so the result is as large as the originals together. Many email services cap attachments at around 20 to 25 MB, so you may need to send the file through a link instead. Our guide on reducing PDF size covers what you can do.

The file went missing. Check the Downloads folder on Android or Files then Downloads on iPhone. Browsers sometimes add a number to the name, such as merged(1).pdf.

Privacy on a phone

Your documents often contain IDs, bank statements or certificates, so where they are processed matters. Toolbyte's merge runs in your browser, which means the files are read from your phone, combined on your phone and saved back to your phone. No copy is stored on our servers. If you want extra caution, use a private tab and close it when you finish.

When you need only some pages

If you only need part of a document, extract those pages first with Split PDF, then merge the pieces. Our guide on splitting a PDF into pages shows how ranges like 1-3,5 work.