How to reduce PDF file size without losing quality
Almost always the weight of a PDF comes from images and scans, not from the text. That is why good compression is about optimising those images without touching the content.
To reduce the size of a PDF, compress it by optimising the images inside: that is what takes up the space. In PDFix Pro compression runs in your browser, leaves the text untouched and is usually enough to fit the file within an email attachment limit.
Step by step
- 1
Work out why it is heavy
A text-only PDF rarely goes beyond a few hundred kilobytes. If yours is several megabytes, it almost certainly contains photos or scanned pages.
- 2
Run it through the compress tool
Add the file and let the embedded images be optimised. Text and links stay exactly as they are.
- 3
Compare before and after
Check the resulting size and open a couple of image-heavy pages to confirm they are still readable.
- 4
If it is still large, split it
When a document full of scans does not shrink enough, separate it by chapters or page ranges and send the parts.
- Scanning in greyscale instead of colour cuts the original size in half or better.
- Avoid compressing the same file twice: the second pass barely helps and can degrade the images.
- For email attachments, aim for under 10 MB; that is the usual limit with most providers.
Frequently asked questions
Does compression lose quality?
The text is untouched. Images are optimised, so there can be a small loss, tuned so they still look good on screen and in normal printing.
How much smaller does a PDF get?
It depends on the content: a document with scans can shrink a lot, while a text-only file is already optimised and barely changes.
Is my file uploaded to a server?
No. Compression happens inside your browser and the document never leaves your device.