How to Reduce PDF File Size to 100 KB, 200 KB or 1 MB

By Shani Dev Gupta · Updated 23 September 2026 · 5 min read

Scanned certificates and documents photographed with a phone often turn into PDFs of 5–20 MB. Most portals accept only a few hundred KB. Here is how to shrink them.

Steps

1. Open Compress PDF and select your file.
2. Choose a level:
   • High gives the smallest file and is best for strict limits such as 100–200 KB.
   • Recommended balances size and readability.
   • Low keeps the best quality and is good for printing.
3. Tap Compress PDF. The tool shows the old and new sizes.
4. If it is still too big, try the next level down, or use the tips below.

Still too big? Try these

• Remove pages you don't need with Remove pages. Blank backs of scanned pages add size.
• Convert to black and white with Grayscale PDF if colour is not required. Grey pages compress much better.
• Split it into parts with Split PDF if the portal lets you upload several files.
• Rebuild from photos: if you made the PDF from phone photos, recreate it with JPG to PDF using the Black & white document scan effect.

Why some PDFs don't get smaller

PDFs exported from Word or Excel are mostly text and are already small. This compressor works by turning each page into an optimised image, which helps scanned files a lot but can make text-only PDFs bigger. If that happens, the tool tells you and keeps your original.

Frequently asked questions