# Compress a PDF to 100 KB

Application portals often refuse documents over 100 or 200 KB. Pick the limit the form asks for and the PDF is shrunk step by step until it fits, as readable as possible.

_Source: https://sharelargefilesfree.com/tools/compress-pdf-to-100kb · Updated 2026-09-29_

**Quick answer:** To compress a PDF to 100 KB, open it here, keep the 100 KB target (or pick 50, 200, 300 or 500 KB) and download the result. The tool first shrinks the images inside the PDF, then turns pages into lower-resolution images until the file fits; one or two scanned pages usually fit in 100 KB. Nothing is uploaded.

## How to use it

1. Choose the PDF the form rejected: a scanned certificate, ID, mark sheet or letter.
2. Pick the size the form asks for: 50, 100, 200, 300 or 500 KB.
3. Press Compress to target and wait while it tries the gentlest method first.
4. Check that the text is still readable on the page, then download it and upload it to the form.

## How many pages fit in 100 KB?

100 KB is tiny: a single phone photo is usually 2 to 4 MB. What fits depends on how the PDF was made:

| PDF | At 100 KB | At 200 KB |
| --- | --- | --- |
| Typed document from Word or Google Docs | Often already under, text stays sharp | Usually fine as is |
| 1 scanned A4 page | Clear, readable | Clear, readable |
| 2 to 3 scanned pages | Readable, fine print gets soft | Readable |
| 5 or more scanned pages | Often too blurry | Soft; split the document if the form allows |

The tool stops at the gentlest step that fits and tells you which one it needed. If it cannot reach the target and stay readable, you get the smallest version with a note instead of an unreadable file.

## Scanning tips for a smaller PDF

- **Scan in black and white or grayscale** if the form does not need colour; colour scans are several times larger.
- **150 dpi is enough** for documents read on screen. 300 dpi or photo mode makes files four times bigger.
- **Crop to the page**: a phone photo with a table around the paper wastes bytes on the table.
- **Only upload the pages asked for**: remove extra pages with [Delete pages](https://sharelargefilesfree.com/tools/delete-pages) or keep one with [Extract pages](https://sharelargefilesfree.com/tools/extract-pages) first.

## Photo and signature uploads are a different tool

Forms often ask for the document as a PDF but the photo and signature as JPG files with their own limits (such as 20 to 50 KB). For those, use [compress image to 50 KB](https://sharelargefilesfree.com/tools/compress-image-to-50kb) or [compress image to 20 KB](https://sharelargefilesfree.com/tools/compress-image-to-20kb), and [JPG to PDF](https://sharelargefilesfree.com/tools/jpg-to-pdf) if a photo of a document has to become a PDF.

## Private by design

Certificates, IDs and mark sheets are personal documents. This PDF is compressed by your own browser and never uploaded to us, so there is no copy on a server and nothing to delete afterwards.

## Frequently asked questions

### How do I reduce a PDF to 100 KB?

Open it here, keep the 100 KB target and press Compress to target. The tool shrinks the images in the PDF first and, if that is not enough, converts pages to images at a lower resolution until the file is under 100 KB.

### Will the text still be readable?

For one to three scanned pages, yes. Longer documents get soft at 100 KB; choose 200 or 300 KB if the form allows it, or upload fewer pages.

### Why can I no longer select the text?

To reach very small sizes the pages are turned into images. The document looks the same but works like a scan. Typed PDFs that fit without that step keep selectable text.

### Can I compress a PDF to 200 KB or 50 KB instead?

Yes. Pick 50, 100, 200, 300 or 500 KB from the target list before you start.

### Is my document uploaded?

No. It is compressed in your browser on your device.