Compress PDF to 100 KB

Compress PDF to 100 KB brings a short scanned PDF under 100 KB for an upload form, re-rendering each page in your browser so the file is never uploaded.

Drag and drop, or click to upload a PDF

PDF file · processed on your device, never uploaded

At a glance

Accepts: One PDF file, best a scanned or photo-heavy one
Outputs: A PDF under 100 KB, or the smallest result it could reach
Where it runs: Entirely in your browser, on your device
What leaves your device: Nothing - the file never leaves your device
Limits: Realistic for up to about 4 scanned pages; stops at 60 DPI to keep text readable; pages are re-rendered as images, so text stops being selectable
Account: Not required - there is no sign-up
Price: Free, with no watermark and no usage cap
Made by: Visrut
Last updated: 8 October 2026

100 KB is a common ceiling on application portals, where each slot holds one document: a mark sheet, an income certificate, a proof of address, a two-page reference letter. It is tight but workable for a short scan. This page starts in "Target file size" mode with 100 KB picked, re-renders your PDF in the browser at falling resolutions, and keeps the sharpest version that comes in under the limit. The file stays on your device the whole time.

What to expect at 100 KB

Results from our 300 DPI A4 test scans:

One page: 48 KB at 72 DPI. Easy to read on screen.
Two pages: 97 KB at 72 DPI. Still easy to read.
A color ID card scan: 71 KB at 96 DPI, a little crisper than the plain text pages manage.
Three or four pages: only at 60 DPI, the last step. Readable, but small print suffers.
Five pages or more: expect a miss.

When this is and isn't the right choice

Right choice: one document of one to four scanned pages going into a portal slot capped at 100 KB.
Wrong choice: you have several documents to send in one slot. Check whether the form really wants them merged; if it does, combining them with Merge PDF and then compressing is possible only if the total is about four pages.
Wrong choice: the portal accepts JPG as well as PDF. A single image is usually simpler to get small with Image Compressor.

Tips for a clean 100 KB file

Start from the best scan you have. A clean 300 DPI scan compresses to a sharper 100 KB file than a blurry phone photo does.
Turn sideways pages upright first with Rotate PDF, so reviewers do not have to rotate a low-resolution page to read it.
Zoom the result to 100% and read a line of the smallest print. If it is the bit that matters, a reference number for example, and it is smudged, scan just that page again in better light.

How to use it

Drop your PDF on the box above, or click to choose it.
Leave "Under 100 KB" selected and click "Compress PDF".
Download the result and check it before you upload it.

Frequently asked questions

How many pages can I fit in 100 KB?

For scanned pages, about four at most, and only at the lowest setting. Two scanned pages fit at 72 DPI (97 KB in our test), which still reads well. One page usually lands far below the limit at a better setting.

Why is my one-page result only about 50 KB when I asked for 100 KB?

The tool tries a fixed set of settings, best quality first, and keeps the first one under your target. If the next step up is just over 100 KB, it has to drop to the step below, which can be roughly half the size. In our test a single 300 DPI scan came out at 100.6 KB one step up, a hair over the limit, so it settled on 48 KB at 72 DPI.

Does the 100 KB limit mean 100,000 or 102,400 bytes?

Forms differ, so the tool aims under 100,000 bytes. That passes either way. The size it shows you uses 1,024 bytes per KB, so a safe result may read as about 97 KB.

Can I compress a certificate with a photo on it to 100 KB?

Usually yes. Photos compress better than you might expect at this size. Our color ID card scan came out at 71 KB at 96 DPI, with the face and printed details still clear.