PDFCure
All tools

Compress a PDF to Under 100 KB, Free

Shrink a PDF down to under 100 KB — for strict portal and form upload limits.

Most tools run entirely on your device

Select a PDF to compress

Click to choose, or drop a file here

You can also paste (Ctrl+V / Cmd+V)

Most tools run entirely on your device

About compressing a PDF to 100 KB

100 KB is a tight target — it's the kind of limit some government portals and older upload forms set. This tool takes a single PDF and re-encodes its images in a loop, dropping the quality one step at a time and checking the size after each pass, until the file is at or just under 100 KB.

It works well on a one- or two-page scan or a form. A long or image-heavy document usually can't reach 100 KB without the text becoming unreadable — in that case the tool gets as close as it can and shows you the size it landed on, so you can decide whether to split the document and upload it in parts.

Everything runs in your browser. If 100 KB is stricter than you actually need, Compress PDF to 200 KB, 500 KB or 1 MB give you more quality headroom, and Compress PDF lets you pick a quality level directly.

Supported files

Accepts a single PDF. Produces a PDF at or under 100 KB (or the smallest it can reach).

Is my file uploaded?

No. The entire size-down loop runs on your device — the PDF is never uploaded.

Common problems

It couldn't get to 100 KB
A multi-page or text-heavy PDF has a size floor. Remove pages you don't need, or split the document and upload it in parts.
The result is unreadable
100 KB forced very heavy compression. Try a 200 KB or 500 KB target instead if the portal allows it.

How to Compress PDF to 100KB

  1. 1

    Add your PDF

    Drop in the file that's over the limit.

  2. 2

    Compress to 100 KB

    It steps through smaller image quality and resolution until it fits, or gets as close as it can.

  3. 3

    Download

    Save the 100 KB PDF, ready to upload to a portal with a tight attachment cap.

Compress PDF to 100KB — frequently asked questions

Will 100 KB always be possible?+

Not always. A short, mostly-text PDF gets there easily. A long, image-heavy or scanned document may not fit without unreadable quality loss — the tool tells you honestly if it couldn't hit the target.

Will the text still be readable?+

Yes — text stays selectable and sharp far longer than images do, since the compression works by re-rendering and shrinking page images, not by degrading text.

Why 100 KB specifically?+

It's a common hard limit on government portals, exam boards, and some job application forms. If your form allows more, try Compress PDF to 500 KB or 1 MB for a better-looking result.

Is there a free way to compress a PDF to under 100 KB?+

Yes — this tool compresses down to 100 KB entirely in your browser, free and with nothing uploaded.

Do you upload my files to a server?+

No — every tool here processes your files entirely on your device, and nothing is uploaded to a server. The only exception is the AI tools, which send the extracted text (not the file) to Claude to do their work.

Is there a file size limit?+

There's no artificial limit we impose, but since processing happens in your browser, very large files (500+ MB or 1,000+ pages) are limited by your device's memory rather than by us.