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Quick answer
To compress a PDF to 500KB, open Compress PDF, add your file and choose Moderate, which makes most files 60–70% smaller. The size is shown before you download. Typed documents often fit on Light, and five to eight scanned pages usually fit on Moderate.
How to compress a PDF to 500KB in 3 steps
Add your PDF
Open Compress PDF and drop in your file. PDFs up to 200 MB work, including scans.
Choose Moderate
Moderate is the best starting point for a 500KB target. The tool shows the original and compressed sizes, so you can check the result straight away.
Check the size and download
If the new size is under 500KB, download it. If not, see the fixes below.
What fits in 500KB
Text barely adds to a PDF's size. Scanned pages and photos are what make it heavy. As a rough guide:
Swipe to compare →
| Your PDF | Level to try | Under 500KB? |
|---|---|---|
| Typed document with a few images | Light | Usually |
| 5–8 scanned pages | Moderate | Usually |
| Brochure or photo-heavy PDF | Moderate or Extreme | Usually |
| Long scanned book or report | Extreme, then split | Sometimes |
If your PDF is still over 500KB
- Try the next level up, up to Extreme.
- Remove blank or unneeded pages with Delete PDF pages, then compress again.
- If it is a scan, re-scan at 150 DPI in grayscale. It makes a much smaller file to begin with.
- Still too big? Split the PDF into two files and upload each one if the form allows it.
Scan settings that land under 500KB
The easiest way to hit 500KB is to create a smaller file from the start. If you are scanning a document for a 500KB limit:
- Resolution: 200–300 DPI is plenty for reading and printing. 600 DPI makes files several times bigger for no visible gain.
- Color: color.
- Pages: up to about eight pages per file.
- Phone scans: use the Notes app on iPhone (Scan Documents) or Google Drive on Android, which crop and flatten pages automatically.
How to check a PDF's size in KB
- iPhone: in the Files app, touch and hold the PDF and tap Get Info.
- Android: in Files by Google, tap the three dots next to the file and choose File info.
- Mac: select the file in Finder and press Command-I.
- Windows: right-click the file and choose Properties, or switch File Explorer to Details view.
Compress PDF also shows the original and compressed sizes on screen, so you can check before you download.
Where you'll run into a 500KB limit
- Insurance claims with photos and receipts.
- Older email systems and web forms with a 500KB attachment limit.
- Portfolio samples and short reports.
- Scanned contracts and signed agreements.
Frequently asked questions
How do I compress a PDF to 500KB for free?
Open Zappy Compress PDF, add your file, choose Moderate and click Compress PDF. The new size is shown before you download, so you can confirm it is under 500KB.
Can every PDF be compressed to 500KB?
Not always. Long scanned documents may not fit in 500KB even on Extreme. Remove pages you don't need or split the file into parts.
Will the text still be readable?
Yes. Compression shrinks images and scans, not text, so typed words stay sharp at every level.
Is 500KB small enough to email?
Easily. Email limits are 20 to 25 MB, so a 500KB PDF sends and opens quickly anywhere.
Is Light enough to reach 500KB?
Often, for typed documents. For scans, start with Moderate.
Does it work on iPhone and Android?
Yes. Open Compress PDF in Safari or Chrome and choose the file from Files or your Downloads.
What happens to my file?
It is compressed on our server and deleted automatically afterwards. It is never shared.