IPHONE
How to make a PDF smaller on an iPhone (iOS 27)
In short
Open the PDF from Files so it opens in Preview. Tap the file name, then Export. Choose PDF, then turn on Optimise Images for Screen and Save Images as JPEG. On ours the estimated size dropped from 4.7 MB to 924 KB. Tap the tick and save the new file.
5 of 5 steps show a real screenshot from our iPhone 17e. Each step was checked against the maker's own instructions, linked at the end.
Steps
- 1
Tap the file name
Open the PDF from the Files app. Tap the name at the top of the screen.
- 2
Tap Export
It is below Duplicate, Move and Rename.
- 3
Choose PDF
The Export Image sheet opened with HEIC ticked on ours, which makes a picture, not a PDF. Tap PDF. The estimate under the list said 4.7 MB.
- 4
Turn on the two image options
Turn on Optimise Images for Screen and Save Images as JPEG at the bottom.
- 5
Check the new size, then tap the tick
Ours said Estimated file size: 924 KB. Tap the tick at the top right, pick a folder and tap Save. We cancelled here instead.
If you do not see this option
- Will it look worse? Apple says Optimise Images for Screen lowers the image resolution for screen viewing. Fine for reading on a screen; keep the original for printing. Source: Export or compress PDFs and images in Preview on iPhone
- What about Compress in Files? Compress in the Files menu makes a zip file, not a smaller PDF.
If this does not work
- The estimate hardly moved? These options shrink pictures. A PDF that is mostly text will not get much smaller.
- Got a picture, not a PDF? Check that PDF has the tick under Format. HEIC was ticked first on ours.
- Cannot find the smaller copy? It is saved in the folder you picked after tapping the tick, not necessarily next to the original. Open Files, go to that folder and look for the new file there.
Good to know
On a Mac, see how to make a PDF smaller on a Mac with Preview. To drop pages you do not need first, see how to rotate, add or delete PDF pages on an iPhone.
The original PDF is not changed; Preview writes a separate, smaller file. That means you briefly have two copies using storage. Once the small one has done its job, you can delete whichever you no longer need, but back up first if the document matters. If space on the iPhone is tight in general, see iPhone storage full: 7 ways to free up space.
About this guide
- Device
- iPhone
- Shown on
- iOS 27.0.1 (iPhone 17e)
- App
- Preview
- Path
- Files › PDF › File name › Export › PDF
- Real screenshots
- 5 of 5 steps
- Checked
- October 2026
- Sources
- 1 official, linked below
Sources
Links checked October 2026. Menus and features can change with updates.Spotted a mistake? Menus change with updates, and we want every step to match your screen. Email us about this page or use the contact form. We read every report, and fixes are listed on What changed.
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