How to reduce PDF file size
Almost every large PDF is large because of the pictures inside it, not the text. Shrink the pictures and most files drop to a fraction of their size while the text stays sharp and selectable.
Do it now, free and without uploading your file.
Open Compress PDF →Why is my PDF so big?
Text costs very little space: a page of plain text is a few kilobytes. What makes a PDF heavy is almost always one of these:
- Scanned pages. A scanner or phone saves every page as a photo, often at 300 dpi in full colour. Ten pages can easily reach 10 MB.
- Photos pasted into a document. A picture taken with a phone keeps its full resolution when it is pasted into Word, even if it is shown small on the page.
- Embedded fonts. Unusual fonts are stored inside the file. This adds a little, rarely more than a few hundred kilobytes.
The quickest way: compress it in your browser
- Open Compress PDF and choose your file.
- Leave the level on Smart. It shrinks only the pictures inside the PDF, so text, links and layout stay exactly as they were.
- Press Compress PDF. You see the size before and after, and if the file cannot get smaller you get the original back instead of a bigger one.
The file is processed on your own device. It is not uploaded, which matters for payslips, ID copies and contracts.
When a form says “maximum 100 KB” or “maximum 200 KB”
Job, exam, visa and university portals often set a hard limit. Pick the matching target in the Compression list, or open the page for that size directly:
Under 100 KB Under 200 KB Under 300 KB Under 500 KB Under 1 MB
DeevitHub PDF first tries shrinking the pictures. Only if that is not enough does it redraw the pages as lighter images, a step at a time, until the file fits. It aims for 100,000 bytes rather than 102,400, because some portals count a kilobyte as 1,000 bytes.
Make the next PDF smaller from the start
- From Word: choose File → Save As → PDF and pick “Minimum size (publishing online)”.
- From a scanner: scan documents at 150 dpi, and in black and white or grayscale when colour is not needed.
- From a phone: use the scanner in your notes or files app rather than the camera; scanner apps crop and flatten the page, which compresses far better.
When it still will not fit
A long document full of colour photos cannot always reach 100 KB while staying readable. Split it with Split PDF and upload the parts, or ask the portal whether a lower-resolution copy is acceptable.
Questions
Does compressing a PDF reduce quality?
Smart compression lowers the resolution of large pictures only. Text, vector graphics and layout do not change. The image-based levels redraw each page as a picture, so text is no longer selectable afterwards.
Why did my PDF not get smaller?
It may already be optimised, or it may be mostly text, which is already tiny. In that case the original is returned unchanged.
Do it now, free and without uploading your file.
Open Compress PDF →