How much smaller will my PDF get after compression?

It depends heavily on the content — image-heavy scans often shrink by 50-90%, while text-only documents shrink only slightly since there are few images to re-encode.

Will compressing my PDF make the text blurry?

No. Compression targets embedded images; selectable text and vector graphics remain sharp at every quality level.

What is the difference between the three compression levels?

Smallest Size prioritizes the lowest possible file size, Balanced is a good default for everyday sharing, and Best Quality keeps images closer to their original resolution for print use.

Do I need an app from the App Store?

No — it works directly in Safari or Chrome on iPhone, with nothing to install from the App Store.

Can I use the Files app or Photos to upload?

Yes — use the Share Sheet from either app to send a file straight into the upload dialog.

Compress

Compress PDF on iPhone

iOS doesn't come with a full PDF toolkit built in beyond very basic viewing, and installing a dedicated app just for an occasional task is overkill for most people. My PDF works directly in Safari or Chrome on iPhone, using the same Files app or Photos share sheet you already know.

Use the Compress PDF Tool

No registration required
Files deleted automatically
Works in any browser

Why This Matters

What Is a PDF Compression Tool?

A PDF compression tool reduces the file size of a PDF, usually by re-encoding the images embedded inside it and streamlining the document's internal structure, while keeping the number of pages, the text, and the overall layout exactly the same. The result is a file that looks the same to the reader but takes up noticeably less disk space and transfers faster.

Step by Step

How to Compress PDF on iPhone

Upload Your PDF

Drag in the PDF you want to shrink, or click to browse and select it. On iPhone, tap the upload area and choose Photos or Files, or use the Share Sheet from either app.

Choose a Compression Level

Pick Smallest Size, Balanced, or Best Quality depending on how the file will be used.

Click Compress PDF

Our server re-encodes the document's images and rewrites its structure, usually within seconds.

Download the Smaller File

Save your compressed PDF — same pages and layout, a fraction of the size.

Recommended Tool: Compress PDF

Reduce file size while preserving visual quality.

Open Compress PDF

Get Better Results

Tips

Match the Preset to the Purpose — Use Smallest Size for quick, informal sharing, and Best Quality when the document is going to professional print.
Don't Compress Twice — Running an already-compressed PDF through compression again rarely reduces size further and can slightly reduce image quality unnecessarily.
Use the Share Sheet from Photos or Files to send an image or document straight into the browser's upload dialog.
iPhone screenshots and photos are usually already in JPG or PNG format, so they work directly with no extra conversion step first.

Avoid These

Common Mistakes

Uploading a file that is already password-protected without unlocking it first — most operations require an unencrypted starting file.
Assuming a converted or compressed file replaces the need for the original — keep your source file until you have confirmed the result looks right.
Not checking the 50 MB upload size limit before starting, then wondering why a very large scan fails to upload.
Installing a separate PDF app from the App Store for a single occasional task instead of using the browser already open.