Gmail always gives you an error when you try and attach a file that’s too large and you exceed their limit.

The annoying thing about reducing PDFs files is that the PDF loses more quality the more you compress it – this then leaves you with a terrible looking PDF.

How PDF Compression Works

A PDF will never retain its full quality when you compress it.

A PDFs quality is measured in dots per inch and most of the time when you upload a PDF, you’re told that the MB for the PDF is too large.

To give you some context, an A4 sheet of paper at 300 DPI is 8.7MB.

So, if you’re uploading a PDF somewhere and it’s longer than an A4 stand sheet of paper, you’ll want to stay reduce it to around 100 DPI so that the PDF doesn’t lose much quality and you can upload it.

Compress PDF from a PDF Reader

If you’ve just made your PDF from a reader like Adobe Acrobat, you’ll be able to compress the PDF from here. There are loads of other PDF readers that you can use to edit PDFs and read them.

If you’re aware that you have a PDF reader, you should open your PDF on the reader. If you have a PDF reader, most of them will have a ‘Save for Web’ option.

To compress a PDF in a reader:

  1. Click on File at the top
  2. Go to Export
  3. Click the option Save for Web
  4. The PDF should be compressed without losing quality

With this method of compression, you don’t have a lot of control over the size of the PDF. The save for web option compresses your PDF whilst retaining a lot of the original quality.

Online Compression Tool

Another way that you can compress a PDF is with an online too. There are many tools but the one that I’d recommend is Ilovepdf – it’s very simple to compress your PDF using this tool and you can control how much it’s compressed by.

Before you compress a PDF with this tool, it shows you the MB of the PDF before and after the compression. This allows you to have some control over what the MB of the PDF will be after you’ve compressed it.

  1. Go to
  2. Click Select PDF files
  3. Choose the PDF you want to compress

Choose compression

  1. Choose a compression level
  2. Click on Compress PDF
  3. The PDF will be compressed without losing quality

If you choose the Recommended option, this will give you a good compression and good quality.

Use a PDF Compression Software

You can download NXpowerlite for both your Windows PC and Mac. This is a PDF compression software that allows you to compress a file based on what you need it for. You can also choose the percentage that you want the PDF to be compressed to.

When you’ve opened your file in the PDF compressor:

  1. Click on File
  2. Export the PDF
  3. Click on the Quartz-Filter menu > select Reduce File save
  4. Click on Save

This is probably the best way to compress a PDF using this software – if you don’t like the way your PDF came out, you can change the percentage that it’s compressed at.