Upload portals, government forms, and job applications love hard size limits — 100 KB, 200 KB, 500 KB — and a phone scan blows past them instantly. The good news: you don't have to guess with quality sliders. Give the compressor a target size and it finds the settings that land under it.
How target-size compression works
Enter the limit you were given (say 100 KB) and the tool walks a quality ladder: it tries progressively stronger image downsampling and re-encoding until the output fits, then returns the best-looking version that made it under the bar. Text is never rasterized, so it stays sharp at every level — it's the images that give up size.
If the target is physically impossible — a 40-page photo scan will never be 100 KB — you'll get the smallest result the file allows instead of a silent failure, so you know where you stand.
When even that isn't enough
Two tricks buy extra headroom. Converting to grayscale drops the color data entirely — often a big win on phone-photographed documents. And if the portal accepts multiple files, splitting the PDF and compressing the parts separately beats squeezing one file to the point of illegibility.