Home › Free tools › PDF Compressor – Reduce PDF Size in KB
PDF Compressor – Reduce PDF Size in KB
Upload limits like 200 KB or 500 KB are common on admission, scholarship and job portals. This compressor rebuilds each page as an optimised image so scanned documents become much smaller, and shows the size before and after.
Before: – · After: –
How to use the PDF Compressor
- Choose the PDF you want to make smaller. Its current size is shown.
- Pick a resolution and JPEG quality, or type a target size in KB to let the tool try levels until it fits.
- Tick Black & white for text documents – grey pages compress much better.
- Press Compress PDF, check the new size and download. Open the result once to confirm it is readable.
This method works best for scanned documents and photos saved as PDF, which is what most applicants upload. Because pages are re-drawn as images, text in a digitally created PDF will no longer be selectable; for such files a lower level may not save much. If the result is not smaller, simply keep your original.
🔒 Privacy: this tool runs entirely in your browser using JavaScript. Your files are never uploaded to Crop Desk or any other server, and you can even use it offline once the page has loaded.
Frequently asked questions
How small can it make my PDF?
It depends on the number of pages and how detailed they are. A one-page scan usually drops to 100–300 KB at 150 DPI, and lower with 100 DPI and black & white.
Why did the size not go down?
PDFs that contain only text are already compact. Re-drawing them as images can make them bigger. In that case keep the original file.
Will the PDF still be readable?
At 150 DPI and 60% quality, normal printed text stays clear. Always zoom in and check before submitting an official form.
Is the file uploaded to compress it?
No. pdf.js draws each page in your browser and pdf-lib builds the new file on your device.