catScan

Compress PDF

Reduce file size while keeping the best possible quality.

Processed on your device

  1. 1Choose the files
  2. 2Arrange and adjust
  3. 3Download

You need to sign in to use the tools. It's free.

8 free uses a month · Plus is unlimited

Make your PDF smaller to send it by email, upload it to a form or save space. Choose the compression level and see how much it was reduced; images are optimized and text stays sharp.

How to compress a PDF in 3 steps

  1. Open the PDF you want to make smaller.

  2. Choose the level: low, recommended or extreme.

  3. Compress and download the lighter PDF.

Why use catScan

  • Private by design

    This tool works inside your browser: the file is processed on your device and is never uploaded or stored.

  • Free to start

    Sign in with Google and get 8 free uses per period, shared with the catScan app. 1 use = 1 downloaded file; if something fails, it doesn't count.

  • Nothing to install

    It works in any modern browser on computer, tablet or phone. To scan paper with your camera, use the Android app.

Frequently asked questions

How much can a PDF be compressed?

It depends on the content. PDFs with many photos or scans shrink the most; PDFs that are mostly text are usually already small. If a file can't be reduced, we tell you and no use is deducted.

Will the text still be readable?

Yes. Compression works mostly on images; text and vector graphics stay sharp. With the extreme level images lose more quality in exchange for a smaller file.

Are my files stored?

No. This tool processes the file on your device, inside the browser: it is not uploaded to any server and nothing is stored.

Is it free?

Yes. Sign in with your Google account and you get 8 uses per period on the free plan (1 use = 1 downloaded file; if something fails, it doesn't count). catScan Plus, bought in the Android app, is unlimited on the web and in the app.

Does it work on my phone?

Yes. It works in any modern browser on Android, iPhone, Windows, Mac or Linux, with nothing to install. The catScan Android app also lets you scan documents with the camera.