PDF too large to email? How to compress, split or merge PDFs on your iPhone

You attach a PDF, hit send, and the email bounces back. The file is too big. Or an upload form says one file only, and you have four.

There are three ways out: make the file smaller (compress), cut it into parts (split), or put several files into one (merge). This guide shows the built-in iPhone options first, then how to do each one in myPDF. We make myPDF, so it’s the tool we know best.

Try the built-in options first

Before you install anything, check whether your iPhone already covers what you need.

• Mail Drop. If you send from Apple’s Mail app and the attachment is too large, Mail may offer to send it with Mail Drop. The file goes to iCloud and the other person gets a download link. That solves “too large to email” without changing the PDF. It doesn’t help when a website or form has its own size limit.
• Create PDF in Files. In the Files app, tap Select, pick several files, tap the … button and choose Create PDF. That combines them into one PDF. It works well for a few images or short files. You get less control over the page order.

If one of those does the job, you’re done. If the file itself has to be smaller, or you need to pick exactly which pages go where, read on.

In myPDF, compress, split and merge are part of myPDF Pro.

How to compress a PDF on iPhone

1. Open Compress PDF and pick the file. It shows the file and its size.
2. Pick an option. Smallest file, Balanced or Best quality, each with an estimate of the new size. The estimates depend on the images in the file.
3. Start it. When it’s done, myPDF shows what you saved, for example “Saved 23.9 MB → 660.2 KB, text kept”, and you can open or share the new file right away.

Text in the PDF stays selectable after compressing.

How to split PDF pages on your phone

Splitting helps when a form only wants some of the pages, or when one big file has to go out in two emails.

1. Open Split PDF and pick the file.
2. Choose how to split it: by page ranges (for example pages 1 to 2 and 3 to 5), or into single pages.
3. Save. Each range becomes its own PDF.

How to combine PDFs on iPhone

1. Open Merge PDFs and add the files you want to join.
2. Put the files in order. The list reads “Files, in this order”. Drag the handle on a file to move it, or tap the minus to remove it.
3. Pick the pages you need. Tap a file to open Select Pages, then tap the pages to keep. Select All takes the whole file.
4. Tap the Merge button. The pages you picked from each file go into one PDF, in the order of the list.

This is handy for job applications: CV, cover letter and certificates in one file, in the order the recruiter expects.

Tips

• Merge first, compress last. If you’re combining files and also need a small result, compress the merged file at the end. That way you only lose quality once.
• Keep the original. Hold on to the full-quality file until the smaller one has arrived, in case someone asks for it.
• Check the result before you send. Open the new file and scroll through it. Make sure small print is still readable and nothing is missing.

What this can’t do

Compression works mostly by shrinking the images inside a PDF. So how much you save depends on the file. A scan or a PDF full of photos can shrink a lot. A PDF that’s mostly plain text is already small, and compression won’t change it much. In that case, splitting is often the better fix.

Compression also has a cost. The smaller you go, the softer images and scanned text get. For a contract or anything with fine print, pick Best quality and check that it’s still legible.

These steps are written for iPhone and iPad. myPDF is on Google Play too, but the screens there may look different.

Quick recap

Too large to email? Try Mail Drop first. If the file itself must be smaller, compress it and check the quality. Need fewer pages? Split it. Need one file? Merge, then compress at the end.