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How to compress a PDF to 100 KB (or any size limit)

Upload portals love hard limits. Set a target size and let the compressor find the settings that land under it — no guessing with quality sliders.

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.

Step by step

  1. Open the Compress tool — Go to the Compress PDF tool and add your file.
  2. Set the target size — Enter the size limit you need to hit, for example 100 KB.
  3. Download the result — The tool finds the strongest settings that fit your target and returns the PDF.