paperfoundry Files stay in this tab · verify it

Paperfoundry / Compress PDF to 100 KB

Compress a PDF to 100 KB

The target is already set to 100 KB. Open your PDF to see whether 100 KB is realistic for it, then let the tool step down until the file fits.

  • No upload, no account
  • No file size cap
  • Keeps working offline once loaded

How to get a PDF under 100 KB

  1. Open the PDF. The panel already says Target: 100 KB and Reach the target.
  2. Read the hint. It tells you how much the file must lose and how many kilobytes each page gets. It also measures sample pages to estimate the result.
  3. Compress. A lossless pass runs first. If that isn't enough, pages are turned into JPEG images, starting at the resolution the estimate suggests and stepping down until the file is under 100 KB.
  4. Check the result before uploading. Zoom in on small print, signatures and stamps. If they are unreadable, use one of the alternatives below instead of sending a blurry file.

Is 100 KB realistic for your file?

What matters is the budget per page: 100 KB divided by the number of pages. A typed one-page letter often fits without any loss. A scanned page needs to become an image of about 80-100 KB, which works at around 120 DPI. Ten scanned pages get only 10 KB each, which means 56-72 DPI and low quality: just readable for large print, not for small print.

Pages (scanned)Budget per pageWhat it takes
1about 100 KBImage-based copy around 120-144 DPI
2-333-50 KBAbout 96 DPI, medium quality
4-714-25 KBAbout 72 DPI; small print gets soft
8 or moreunder 13 KBOften not readable; split or remove pages

If it won't fit

  • Remove pages that aren't required with Organize pages; blank backs of scans are the usual suspects.
  • Split the file with Split PDF if the portal accepts several uploads.
  • Rescan at a lower resolution in black and white if your scanner offers it; that often beats compressing afterwards.

Need a less strict limit? Try compress to 1 MB or the main Compress PDF tool with your own target.

Compress PDF to 100 KB: questions and answers

Why do so many portals ask for 100 KB?

Older application systems store every upload in a database with a small size limit. The limit has stayed even though most PDFs are now larger.

Will my PDF still be readable at 100 KB?

For one to three scanned pages, usually yes. For many pages, the budget per page gets so small that small print blurs. Check the result before you upload it.

Does it compress to exactly 100 KB?

It aims for at or below 100 KB. The final size depends on the page content, so you may get, say, 84 KB.

What if the tool can't reach 100 KB?

You still get the smallest readable version and a clear message. Then remove unneeded pages or split the file, and try again.

Can I keep the text selectable?

Only if the lossless pass alone gets the file under 100 KB, which happens with short typed documents. Otherwise the pages become images.

Are my files uploaded anywhere?

No. The PDF is read into this browser tab and processed by JavaScript running on your device. The result is created in memory and saved by your browser. You can check this yourself in the Network panel.

Does it work without an internet connection?

Yes, once the page has finished loading. The PDF code is downloaded when the page opens, so you can switch off Wi-Fi and keep working in the same tab. Reloading the page needs a connection again.

Is anything saved in my browser?

Only your settings for each tool, such as the chosen format or margin, are kept in this browser's local storage so they are ready next time. Files and page thumbnails are never stored; they disappear when you close or reload the tab.

More PDF tools