Free · Open source · No upload
Get any file to the exact size you need.
Compress, convert and sign PDFs and photos in your browser. Your files are never uploaded.
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How it works
Choose a file
Select or drop a PDF or photo into the workspace.
Set your target
Pick an exact size limit or strength goal.
Download
Get your file instantly without leaving your browser.
Questions
Are my files sent to any server?
Is Weesize really completely free?
How does exact-size compression work?
Does it work offline?
Compress PDF to 100 KB
Get any file to the size you need. Privately.
1 Add the PDF. This page already sets the goal at 100 KB.2 Compress on this device. Text is not rewritten. Images shrink only while the new file is smaller.3 Read the size your system reports. If it is above 100 KB, that is the floor for this file, not a failed upload.
About this tool
One hundred kilobytes is what people type when a form says “small PDF” and never defines small. A one- or two-page grayscale scan of a typed form can approach it. A color photo of a certificate often cannot unless it is cropped tight. This page sets 100 KB as the goal. It will not claim the download is 100 KB if the pages do not get there. A muddy seal is worse than a 180 KB file a clerk can read.
Compress PDF to 100 KB stays on this device. The download is the copy you keep, and Weesize does not store a second one. Close the tab when you are finished and the bytes are gone.
- No upload: the 100 KB goal is applied here, and the PDF is not posted to a compressor.
- Speed: the file does not travel to a server and back, so the wait is only the work itself.
- Quality: the original is kept when the new file would be worse or is not actually smaller.
FAQ
How do I compress a PDF to under 100 KB without losing text readability?
Add your PDF to the Weesize compressor. The client-side engine re-encodes scanned images to optimal resolution while preserving vector text and fonts intact. Because text streams remain untouched, words stay completely sharp at 100 KB.
Can a multi-page scanned document reach 100 KB?
A clean 1 to 2 page grayscale document can reach 100 KB comfortably. However, a multi-page color scan may require aggressive downsampling; if reaching 100 KB would make signatures unreadable, Weesize stops at the safe quality floor.
Why did my file land at 115 KB instead of exactly 100 KB?
Weesize treats 100 KB as a target ceiling, not a destructive cutoff. If compressing pictures further would blur essential numbers or stamps into illegibility, the compressor delivers the smallest readable copy rather than corrupting data.
Is it safe to compress confidential financial or legal forms to 100 KB here?
Yes. All compression operations run locally inside your browser via WebAssembly. Your confidential forms, contracts, and tax documents are never uploaded to remote servers, stored in databases, or viewed by third parties.
Can I use this 100 KB PDF compressor completely offline without Wi-Fi?
Yes. Because Weesize operates entirely client-side, you can load the page once, turn off your internet or switch to airplane mode, and compress files offline. The file processing never makes a network request.
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Last updated 2026-09-27.