Compress a PDF to under 500 KB
University and job portals, scholarship applications and many public procedures accept documents of up to 500 KB. The target of 500 KB is already filled in below: drop your PDF, press Compress and download a file that fits.
Drop your PDF here
or pick a file from your device
- Drop your PDF onto the box or press Select PDF. Nothing is uploaded: the file is read inside this tab.
- Leave Smart selected and the target at 0.5 MB. CLEKARA tests sample pages with every profile and picks the gentlest one that gets under 500 KB.
- Press Compress PDF. The result is opened and checked; the message tells you whether the target was reached and the exact final size.
How it gets under 500 KB
Under 500 KB a scanned page has to be light: about 150 dpi and in grayscale is usually the sweet spot. A 10-page colour scan at 300 dpi will rarely get there without first converting it to grayscale.
Compression runs on Ghostscript compiled to WebAssembly, inside your browser. If even the strongest profile is not enough, it lowers the resolution of the images step by step (80, 60 and 45 dpi) until the file fits, and the message says how far it went. If it still cannot fit, you get the smallest valid result with suggestions — never a broken file.
When the target cannot be reached
Most of the weight in a PDF comes from images. A file that is already optimised, or mostly text with embedded fonts, has little left to remove. Digitally signed PDFs are blocked on purpose, because rewriting them would invalidate the signature.
Frequently asked questions
My scan does not get under 500 KB. What else can I do?
Convert it to grayscale first with the PDF to grayscale tool, remove blank or unneeded pages, and then compress again. If it is still too heavy, split it into two files if the portal accepts several attachments.
Is my document uploaded to a server?
No. The PDF never leaves your device; the compression engine runs in this browser tab.
Can I choose a different size?
Yes. Change the number in “Optional target size” to any value in MB, or use the links above for other common sizes.
Is it free?
Yes, with no account, no watermark and no daily limit.