Increase the Contrast of a PDF to Sharpen & Darken Text

Oct 24, 2011 - 13 Comments

Increase contrast of a PDF

With Preview you can adjust the contrast of a PDF, this makes the text sharper and darker, and for scans or dubious quality PDF’s this makes them significantly easier to read.

  • Open the PDF with Preview
  • From the ‘File’ menu, choose “Export”
  • Click on the “Quartz Filter” drop-down menu and choose “Lightness Decrease”
  • Choose “Save”

For a very practical example, I noticed this was sorely needed after downloading Guy Kawasaki’s freely available “The Macintosh Way” book, which is a great look at early Apple history. Unfortunately the PDF’s text is very light making it difficult to read, but the Quartz Filter mentioned above greatly helps this. The downside you may notice with some files (including The Macintosh Way) is an increase in noise. That noise is most noticeable on older PDF’s of scanned books or documents, and at times the trade-off may not be worth it.

Increase the contrast of a PDF to make the text more readable

Enjoy this tip? Subscribe to the OSXDaily newsletter to get more of our great Apple tips, tricks, and important news delivered to your inbox! Enter your email address below:

Related articles:

Posted by: Paul Horowitz in Mac OS X, Tips & Tricks


» Comments RSS Feed

  1. Chris says:

    Coincidentally resaving it like this finally allowed iBooks to read that book

  2. […] Increase the Contrast of a PDF to Sharpen & Darken Text Increase the Contrast of a PDF to Sharpen & Darken Text… Source: […]

  3. angelo says:


  4. Ellen says:

    Fantastic tip, thank you!

  5. disser says:

    Brilliant. Really pleased this was so simple. No softwares, no rubbish.

  6. B says:

    Faint pdf scans were driving me crazy – thank you so much for the extremely useful tip!

  7. George says:

    This doesn’t work on my mac. There is no export in the file menu.

    • Danny says:

      George, did you open the PDF with “Preview”? Find the file in Finder, CTRL + Click and choose Preview. Should be able to Export from Preview.

      • Glenski says:

        I just downloaded the Preview for Windows application. It does not show Export from the File menu tab. Now what? I opened the PDF using Preview, but now I can’t do this operation.

  8. Zeff says:

    Thanks for taking the time to write this up. This is exactly what I needed!

  9. Narcho says:

    THANK YOU!!! Very helpful! If you can think it, you can do it on a Mac!

  10. grace says:

    what about if you don’t have preview anymore

Leave a Reply


Shop for Apple & Mac Deals on

Subscribe to OSXDaily

Subscribe to RSS Subscribe to Twitter Feed Follow on Facebook Subscribe to eMail Updates