How to reduce a PDF to 200 KB
- Tap Choose the scanned PDF and pick your file.
- The 200 KB target is already filled in — tap Compress to 200 KB.
- Open the result and zoom into the smallest text on the page.
- Save it once you are satisfied that it can be read.
The size where a multi-page scan stays readable
Most documents people compress run to two or six pages: a marksheet with its reverse, a set of experience letters, an application with its annexures. At two hundred kilobytes each of those pages gets thirty to a hundred kilobytes, which is enough to keep printed text crisp and a rubber stamp legible.
It is also the point at which dropping to grey usually stops being necessary. The search tries every colour setting first and only takes the colour out if nothing else reaches the target, so a certificate with a blue seal on it normally keeps its seal at this size.
When your file is already under the limit
If your PDF is 150 KB there is nothing useful to be done to it, and this page will not invent work to look busy. Where the best it can achieve saves less than three per cent, you get your original file back, unchanged, with a line saying why. A fresh file that is one kilobyte smaller and slightly softer is not an improvement.
The same goes for a scan that was already stored in the black-and-white fax format that document scanners produce. Those pages are close to as small as they go, and re-encoding them as photographs would make the document bigger, so they are copied through untouched and the page tells you it did that.