How to compress PDF to 20KB
- 1Choose or drop your PDF into the box above.
- 2Leave the target at 20KB, or adjust it if your form has a different limit.
- 3Turn on Black & white for scanned documents — it saves a lot of space.
- 4Press Compress, check the result size, and download.
Compress PDF to 20KB: key facts
- Price
- Free — no sign-up, no watermark
- Privacy
- Runs in your browser; files are never uploaded
- Output
- PDF under 20KB, same page count
- What fits in 20KB
- A single page, ideally a clean black-and-white scan with mostly text
- Method
- Pages re-rendered as JPEG; DPI and quality tuned to hit the limit
- Works on
- Any modern browser — Android, iPhone, Windows, Mac
- Offline option
- FramePDF Android app (free)
Who asks for PDFs under 20KB?
A 20KB ceiling is common on very strict portals — some state recruitment boards and older government sites built for tiny scanned slips. These limits exist because the portals were built to handle thousands of uploads at once, not because your document needs to be that small.
In practice, 20KB comfortably fits a single page, ideally a clean black-and-white scan with mostly text.
How this tool hits the exact size
Instead of guessing a "low / medium / high" setting, the tool searches for the best combination of resolution and image quality that lands just under 20KB. It starts at 150 DPI and steps down only as far as it has to — never below the point where text becomes unreadable.
Pages are re-saved as images, which is what most portals expect from a scanned certificate. If you need selectable text, keep your original as well.
Tip
At 20KB, turn on Black & white. A one-page grayscale scan at around 60 DPI usually stays readable; a colour photo of a page almost never will.