Compress PDF to 150 KB

Extreme compression is pre-selected to hit this limit.

Your files stay on this device — 0 bytes uploaded

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or drag & drop — pasting works too (Ctrl+V)

How to compress a PDF to 150 KB

150 KB sits in the awkward middle: too tight for a heavy scan, comfortable for most everyday documents. Extreme compression is pre-selected so you clear the limit on the first attempt rather than creeping up on it.

Where this limit shows up

It is a favourite of examination boards and recruitment portals, which often cap a certificate or mark sheet at 150 KB while allowing more for a photograph. If you are uploading a scanned certificate, this is very likely your target.

Getting a scan under the line

Rescan at 200 DPI rather than 600 if you can — resolution, not page count, is usually what blows the size up. Failing that, remove blank pages the scanner added with Remove Pages. Related targets: 100 KB and 200 KB.

Need a different size limit?

Frequently asked questions

Why do portals ask for 150 KB specifically?

It is small enough to store cheaply at scale and large enough for a legible one-page scan, so it became a common default on application systems.

My certificate scan is 4 MB. Can this fix it?

Almost certainly. A 4 MB scan is a high-resolution photograph of a page, which is exactly the case where compression gives the biggest reduction.