# Compress PDF to 100 KB

> Reduce a PDF to under 100 KB in your browser. Lossless first, then the sharpest page images that fit. Shows the exact byte count. No upload.

URL: https://tools.cuelark.com/compress-pdf-to-100kb
Publisher: Cuelark Team (https://cuelark.com)
Updated: 2026-11-10
Price: free, no sign-up
Privacy: runs in the browser; files are not uploaded

Many application portals cap documents at 100 KB. Drop the PDF and get one at or under 100,000 bytes, as sharp as that size allows. One or two scanned pages usually fit; longer documents may need splitting, and the page says so.

## How to use it

1. Drop the PDF. The limit is already set to 100 KB; switch it if the form asks for another size.
2. Turn on Grayscale for black-and-white scans, then press Compress.
3. Check the byte count (it must say under 100 KB) and download. If it cannot fit, split the PDF or remove pages and try again.

## Details

- **Step 1, lossless:** The PDF is rewritten with compressed object streams and unused objects dropped. Text, links and bookmarks stay; often 5–30% smaller
- **Step 2, if needed:** Pages are rendered with pdf.js and stored as JPEG at the highest resolution (150 down to 72 DPI) and quality (85 down to 35) that fits
- **Target:** At or under the limit in bytes (1 KB = 1,000 bytes, so it also passes a 1,024-byte check)
- **If it cannot fit:** You get the smallest readable version and its exact size, with a note, instead of an unreadable file
- **Engine:** pdf-lib and pdf.js, downloaded once and run in this tab. Password-protected PDFs need the password removed first

## Questions

### How many pages fit in 100 KB?

About one or two scanned pages. A text-only PDF exported from Word or Google Docs can hold many more pages, because its text is not an image and the lossless step often brings it under 100 KB on its own.

### The form needs under 100 KB but my scan is 2 MB. Will it be readable?

Usually, for one or two pages. In our test, a noisy 1.65 MB two-page A4 scan came down to 98,409 bytes at 72 DPI, which is the floor we allow. Clean scans with white paper fit at a higher DPI. The result line shows the DPI used, so you can check before uploading. For longer scans, split the PDF and upload the pages separately if the form allows.

### Are my files uploaded?

No. The page loads its code once, then reads and processes your files inside the browser tab. Nothing is sent to a server; you can confirm it in your browser's network panel while a file is processed.

### Will the text still be selectable?

If the lossless step reaches the limit, yes: nothing about the content changes. If pages had to be turned into images to fit, the new file looks the same but its text cannot be selected or searched. The page tells you which one happened.

### Why does 72 DPI stop the search?

Below about 72 DPI, normal 10–12 pt body text in a page image becomes hard to read, and a portal that accepts the file may still reject an unreadable document. You get the smallest readable version and a clear message instead.

### My PDF is a scan. How small can it go?

A scanned page is already a picture, so the tool re-renders it at a lower resolution. Clean scans on white paper shrink the most; grainy phone photos of paper and colour pages need more bytes. Turn on Grayscale for black-and-white documents, and check the DPI shown in the result.

### Does 500 KB mean 500,000 or 512,000 bytes?

The tool aims at or under 500,000 bytes, so the file passes either way of counting. The exact byte count is shown before you download.

## Related tools

- [Compress PDF to 200 KB](https://tools.cuelark.com/compress-pdf-to-200kb)
- [Compress PDF to a size you choose](https://tools.cuelark.com/compress-pdf)
- [Split PDF](https://tools.cuelark.com/split-pdf)
- [Compress image to 100 KB](https://tools.cuelark.com/compress-image-to-100kb)