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Pdfiqo

Compress a PDF to 100 KB

Meet the tightest upload limits without sending your file anywhere.

Drop a PDF hereYour files stay on this device.Choose files
  • Processed on your device
  • Works offline once loaded
  • No sign-up, no watermark

How to compress a PDF to 100 KB

  1. 1

    Add your PDF

    Drop the file on the page or click to pick it. It opens in this tab and is never uploaded.

  2. 2

    Keep the 100 KB target

    Target size already reads Under 100 KB. Leave it, or switch to Custom if your form allows a little more.

  3. 3

    Compress and check the size

    Click Compress PDF. The result shows the new size and whether it fits under 100 KB, then you download it.

Why 100 KB comes up so often

A 100 KB cap is common on older government portals, exam registrations and some job boards. These systems were built to store thousands of small attachments, like a signature, a photo ID or a one-page certificate, and they reject anything bigger. The limit feels strict because it is: a single phone photo is usually several times larger.

How the tool gets there

Most of the weight in a scanned PDF is image data. With the target set, the compressor first tries the Balanced setting. If the result is still too big, it steps down image quality and resolution in a few passes and keeps the best-looking version that fits. The lowest step keeps images at around 50 DPI, which is enough to read a scanned page on screen but not to print it nicely.

Everything else in the file stays untouched: selectable text, fonts, links and vector drawings. That is also the limit of this approach. A text-only PDF has no photos to squeeze, so it may barely move.

What to expect

  • One or two scanned pages: usually fits, with softer but readable images.
  • A photo ID or certificate: fits well, since it is one image on one page.
  • Ten or more scanned pages: often too heavy for 100 KB. Send only the pages that are asked for.

When it does not fit

Cut the document down first. Delete pages removes what the form does not need, and Split PDF turns a long file into parts you can upload separately. A color scan of a black and white page also wastes space, so try Grayscale PDF before compressing. If your portal accepts a bit more, the 200 KB version keeps images noticeably clearer.

Your file stays in this browser tab the whole time. Nothing is sent to a server, and you can close the tab when you are done.

Frequently asked questions

Can any PDF be compressed to 100 KB?

Not always. A short scan or a few photos usually fits. A long document full of text, fonts and drawings may already weigh more than 100 KB before any image is touched, and those parts are not shrunk here.

Will the text still be readable at 100 KB?

Yes. Text and vector graphics are kept exactly as they are. Only the photos and scanned images get smaller, so words stay sharp even when pictures turn soft.

What happens if 100 KB is out of reach?

You still get the smallest version the tool could make, marked Target not reached. It is never larger than your original. Removing pages or splitting the file is the next step.

Is 100 KB here the same as 100,000 bytes?

Sizes are counted in binary units, so 100 KB means 102,400 bytes. If a form counts 100,000 bytes, set a Custom target of 97 KB to be safe.