Compress PDF to 50KB online.
Free. No sign-up. Exactly 50KB — your files never leave your browser.
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100% Local ProcessingYour files stay on your device
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Zero UploadsNo tracking, nothing leaves
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Fast & EfficientSeconds, right in your browser
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Free Batch ModeNo limits, no registration
Drop your PDF here
or click to browse — multiple files = free batch mode
All files will be compressed to the same target size, one after another. Free batch — no per-file limits.
For files over 50 MB, a desktop tool may work better — but you can still try.
Compressing…
Preparing…
Done.
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Your files never leave your device. Total privacy, guaranteed by design.
Processing happens instantly in your browser. No waiting, no queue.
Press F12 and watch the Network tab: zero uploads, every single time.
Every tool, every batch, no hidden costs. Use unlimited.
How do we keep your files private?
Do you upload my files to a server?
Never. PDF Slim runs entirely in your browser — pages are rendered and re-encoded on your own device. Your files don't touch our servers for even a second.
How can I verify that myself?
Press F12 to open Developer Tools, click the Network tab, then compress a PDF. You'll see zero uploads. In fact, you can disconnect from the internet and compression still works.
Do you track me or use cookies?
No cookies, no tracking pixels, no analytics. There's nothing to sign up for and nothing stored about you — the only thing saved is a local counter of bytes processed on your own device.
Why compress to 50KB?
Why exactly 50KB?
Government ID services, visa applications and some of the strictest online portals cap document uploads at 50KB — one of the most demanding limits on the web. PDF Slim hits it by re-encoding pages step by step until the file fits, entirely on your device.
Will my document still look good?
Government ID portals, visa applications and e-filing systems frequently demand documents under 50KB.
Is it really free and unlimited?
If your PDF is mostly text, 50KB is usually achievable with no visible difference at all.
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and counting — every byte stayed on a device like yours.