Compress PDF

Make a PDF smaller. Light keeps every page exactly as it is. Strong makes scans and photo-heavy files far smaller by redrawing each page as a picture.

How the files you choose are handled is set out in the privacy policy.

How to compress a PDF

  1. Tap Choose a PDF.
  2. Choose Strong for a scan or a file full of photos, or Light to keep the pages untouched.
  3. With Strong, pick a sharpness and a picture quality.
  4. Press Compress PDF. The result shows the old size, the new size and the saving.

Light or Strong?

This PDF compressor works in two ways, and the right choice depends on what is making the file big.

PointLightStrong
What it doesPacks data that was stored loosely in the fileRedraws every page as a JPEG picture
Pages afterIdenticalLook the same at normal zoom, softer when enlarged
TextStill selectable and searchableBecomes part of the picture
Typical savingUsually small, sometimes noneLarge on scans and photo-heavy files
Best forPDFs written by older or simpler softwareScanned documents, phone-photo PDFs, slides with pictures
Avoid forScans, where it saves littleText documents you will search, copy from or sign electronically

The tool refuses to hand back a file that is not smaller. If Light finds nothing to pack it says so, and you can decide whether Strong is acceptable for that document.

Sharpness and quality, in Strong mode

  • Screen, 72 dpi is enough for reading on a phone or laptop and gives the smallest file.
  • Balanced, 110 dpi stays readable when zoomed in a little, and prints acceptably.
  • Print, 150 dpi is for documents that will be printed or that contain small type.

Picture quality sets how hard each page is squeezed. Lower quality adds a slight haze around letters. For a form that has to be legible but not beautiful, 72 dpi at Medium is usually the best trade.

Sizes to aim for

Where it is goingUsual limit
Email attachment20 to 25 MB for the whole message
Job and university application portalsOften 2 to 5 MB per file
Government and visa formsOften 1 to 2 MB, sometimes a few hundred KB
Messaging appsLarge, but small files send faster on mobile data

These are typical figures, not rules. The form or service you are using states its own limit.

Other ways to make a PDF smaller

  • Send fewer pages. Extract PDF pages to keep only what the reader needs.
  • Shrink the pictures before they go in. If the PDF was made from photos, make the photos smaller with the image converter and rebuild it with JPG to PDF.
  • Split it. Split PDF into parts that each fit under the limit.

Password-protected PDFs can be compressed in Strong mode if you know the password. You are asked for it when you choose the file.

Questions

How do I reduce a PDF to under 1 MB?

Use Strong with Screen, 72 dpi and Lower quality. If it is still too large, the document has too many pages for that limit: extract the pages you need, or split it.

Will compressing make my PDF blurry?

Light never changes the pages. Strong softens them slightly. At 110 dpi and Medium quality most documents remain comfortable to read.

Why did Light not make my file smaller?

The file was already packed tightly. That is common for PDFs saved by current word processors and scanners.

Can I still select text after compressing?

After Light, yes. After Strong, no, because each page is now a picture.

Why is my PDF so large in the first place?

Usually pictures. A scan at 300 dpi in colour, or pages built from phone photos, can run to several megabytes per page.

Last reviewed .

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