How to reduce PDF file size on iPhone
Quick answer: To reduce a PDF's file size on iPhone, open quickpdfapp.com/compress-pdf in Safari, sign in and tap Choose PDF. Pick Balanced, which shrinks photos inside the file but keeps text sharp, and download the smaller copy. If it's still too big, try Smallest, check the size in Files, or split the PDF into parts.
Sign in with Google or email and start editing. Saving your file starts a free trial: 7 days on yearly ($29.78/yr) or 2 days on monthly ($2.99/mo). Cancel anytime. 🔒 Your file stays on your device.
Scanned documents and PDFs full of photos get big fast. Then an upload form says the file must be under a limit, or an email bounces. iPhone has no compress button for PDFs, so you need a tool that does it.
This guide shows how to make a PDF smaller on iPhone or iPad with Quick PDF, how to check the file size, what each compression level does to your document, and what to do when one round of compression isn't enough.
Reduce PDF file size on iPhone with Quick PDF
- Check the current size In the Files app, long-press the PDF and tap Get Info (or Info) to see its size. Note the limit you need to get under.
- Open Compress in Safari Go to quickpdfapp.com/compress-pdf, sign in, tap Choose PDF and select the file.
- Choose a level Pick Light for small changes and the best quality, Balanced (recommended) to shrink photos while keeping text sharp, or Smallest to shrink as much as possible.
- Download and compare Download the compressed PDF to Files, then check its size with Get Info again.
- Go further if needed Still over the limit? Run the original through Smallest instead of Balanced. Keep in mind Smallest turns each page into an image, so text can no longer be selected.
- Split if it's still too big For very large files, split the PDF into two or more parts with Split and send them separately, or compress each part.
Light, Balanced or Smallest: which to pick
| Level | What it does | Good for |
|---|---|---|
| Light | Small changes, best quality | Files that are only a little over a limit |
| Balanced | Shrinks photos inside the PDF, keeps text sharp and selectable | Most documents: forms with photos, reports, statements |
| Smallest | Every page becomes a compressed image | Scans, photo-heavy files, strict upload limits |
There's no box to type a target size. Instead you pick a level and see the result. How much a file shrinks depends on what's inside it: PDFs made of phone photos or scans can shrink a lot, while a text-only PDF is usually small already and won't change much. Start with Balanced and only move to Smallest if you need to.
How to see a PDF's file size on iPhone
iPhone hides file sizes by default. To check one:
- In the Files app, long-press the file and tap Get Info. The size appears under the name.
- Or switch the folder to List view (the icon at the top right) to see sizes under each file name.
Sizes are shown in KB or MB. 1 MB is about 1,000 KB, so a 1,450 KB file is roughly 1.4 MB. If you need to get under a very small limit, read how to compress a PDF to 1 MB.
Why PDFs from an iPhone get so large
- Phone photos are high-resolution. A PDF made from a few full-size camera photos can easily reach several megabytes per page.
- Scans store each page as a picture. Even a one-page letter becomes an image.
- Merged files add up. Combining ten documents gives one file with all their weight.
You can prevent some of this when creating the PDF: the Scan to PDF tool's Document look (black and white cleanup) produces lighter pages than full colour. More background in why is my PDF file so large.
Other ways to send a big PDF from iPhone
Compression isn't the only route:
- Mail Drop: when an attachment is too large, the iPhone Mail app offers to send it with Mail Drop, which shares a download link through iCloud instead of attaching the file.
- A cloud link: share the file from iCloud Drive or Google Drive as a link.
- Split it: send the document in two or three parts with Split.
Upload forms on websites usually need the actual file, though, and many email services cap attachments at around 20-25 MB (Gmail allows 25 MB, Outlook.com 20 MB). For those, compressing is the reliable fix. See PDF too large to email.
Troubleshooting compression on iPhone
- The file barely got smaller. It's probably mostly text already. Try Smallest only if size matters more than selectable text, or split the file.
- The text looks blurry after compressing. You likely used Smallest. Go back to the original and use Balanced.
- I can't copy or search the text any more. That's how Smallest works: pages become images. Use Balanced to keep text selectable.
- The PDF is password-protected. Remove the password with Unlock first, then compress, and protect it again afterwards if needed.
- The download didn't replace the original. It's a new file, usually in Downloads. Delete the old one if you no longer need it.
Questions people ask
How do I make a PDF smaller on my iPhone?
Open Quick PDF's Compress tool in Safari, choose the PDF and pick Balanced. Download the result and check the size in the Files app with Get Info. If it's still too large, try Smallest, or split the document into parts.
Does iPhone have a built-in way to compress a PDF?
There's no compress button in the Files app. People who like automation can build a shortcut in the Shortcuts app to shrink PDFs, but it takes some setup. A compress tool in Safari is the simpler option for most people.
Can I compress a PDF to an exact size on iPhone?
Not to an exact number. Quick PDF has three levels, and the size you end up with depends on what the PDF contains. Try Balanced first, then Smallest, and check the size each time. Splitting the file is the fallback for strict limits.
Will compressing a PDF ruin the quality?
Light and Balanced keep text sharp; Balanced mainly shrinks the photos inside. Smallest turns pages into compressed images, which makes the file much smaller but means the text can't be selected and fine details may soften.
How do I reduce PDF size on iPad?
Use the same steps in Safari on iPad: open the Compress tool, choose the file, pick a level and download. Check the new size by long-pressing the file in the Files app and tapping Get Info.
Is my PDF uploaded when I compress it?
No. Quick PDF compresses the file inside Safari on your iPhone or iPad, so the document stays on your device. That matters for bank statements, IDs and medical records.
Do I have to pay to use Quick PDF?
You can open a PDF and edit, sign or fill it after signing in with Google or email. To download, print or share the finished file you start a subscription with a free trial: 7 days on the yearly plan ($29.78 per year) or 2 days on the monthly plan ($2.99 per month). You are charged when the trial ends unless you cancel, and you can cancel anytime.
Sign in with Google or email and start editing. Saving your file starts a free trial: 7 days on yearly ($29.78/yr) or 2 days on monthly ($2.99/mo). Cancel anytime. 🔒 Your file stays on your device.