Compress PDF
Optimize & shrink PDF size.
Compress PDF at a glance
Compress PDF is a free online pdf tool you can use right now to optimize & shrink PDF size โ no account, no install and no usage limit. It runs entirely inside your browser, so whatever you enter stays on your own device.
- Price
- Free โ no trial, no paid tier, no watermark
- Sign-up
- Not required
- Where it runs
- In your browser โ nothing is uploaded to a server
- Works on
- Chrome, Safari, Firefox and Edge โ desktop, tablet and phone
- Category
- PDF & File Tools
Rebuilds the PDF structure (object streams). Best on unoptimized PDFs; image-heavy files compress less.
About Compress PDF
Compress PDF shrinks an oversized document so it fits an email attachment limit or an upload cap. Most of the weight in a large PDF is images, so that's where the savings come from โ the images are re-encoded at a lower quality while the text layer is left untouched and stays perfectly sharp.
How much you save depends entirely on what's inside. A text-heavy report may barely shrink because there was little to remove. A file full of phone photos or scanned pages often drops by 60-90%, because camera images carry far more pixel data than a printed page needs.
Worth knowing: compression is lossy for images and can't be undone, so keep your original if the document is going to print. For email, web upload or archiving, the difference is usually invisible.
How to use Compress PDF
- Enter your input.
- Get your result instantly.
- Copy or reuse it however you like.
Frequently asked questions
Why did my PDF barely get smaller?
It was probably already efficient โ a text-only PDF has little to compress. The big wins come from documents containing photos or scanned pages, where the image data dominates the file size.
Will the text become blurry?
No. Text in a PDF is stored as vector glyphs, not pixels, so it stays sharp at any zoom. Only embedded images are re-encoded.
Can I undo the compression?
No โ image compression discards data permanently. Keep your original file if you may need full quality later, for example for professional printing.
Is my file uploaded?
No. Compression runs in your browser and your document never leaves your device.