Compress PDF
Compress a PDF for free, right in your browser. Upload your file, pick a compression level, and download a smaller PDF with a before-and-after size comparison. Pages are re-rendered as optimized images, which shrinks scans and image-heavy documents dramatically, and the tool never produces a file larger than your original. Your file never leaves your device.
Pages are re-rendered as optimized images, which shrinks scans and image-heavy PDFs dramatically. Text stays readable but is no longer selectable, so keep your original if you need to edit it later.
Last reviewed: July 2026
What makes a PDF large, and what compression does
PDF size is dominated by images. A page of plain text is tiny, but a single high-resolution scan can be several megabytes, which is why scanned documents so often exceed email and portal limits. This tool shrinks a PDF by re-rendering each page as an optimized image at a sensible resolution, then rebuilding the document. For scans and image-heavy files, that routinely cuts the size by well over half.
How to compress a PDF
- 1
Upload your PDF
Click or drag your file into the box. The tool shows its current size.
- 2
Choose a compression level
Pick high quality, balanced, or small file depending on how much size matters versus image sharpness.
- 3
Compress
Each page is re-rendered as an optimized image on your own device.
- 4
Compare and download
Check the before-and-after size, then save the smaller PDF.
Your file is processed on your own device and is never uploaded to a server.
Choosing a compression level
- High quality keeps pages sharp at roughly print resolution. Use it for documents people will read closely or print.
- Balanced is the best trade-off for most documents shared on screen, like email attachments and portal uploads.
- Small file compresses hardest. Use it when a strict upload limit matters more than image crispness.
If the result is larger than you hoped, run the original again at a stronger level rather than re-compressing the output. Compressing an already-compressed file compounds the quality loss without saving much more.
The quality trade-off, honestly
Because pages are re-rendered as images, the compressed PDF looks like the original but behaves like a scan: text stays readable and printable, but it can no longer be selected, copied, or searched. That is the standard trade-off image-based compressors make, and it is why we recommend keeping your original file for editing. If your PDF is mostly text and already small, compression cannot help, and the tool will tell you so rather than produce a larger file. It never outputs a file bigger than your original.
Compressing on Windows, Mac, or your phone
The tool runs in any modern browser, so it works the same on Windows, Mac, Linux, ChromeOS, iPhone, and Android. There is nothing to install and no software to buy. Upload your PDF, pick a level, and download, whether you are on a laptop or a phone.
Is it free, and is my file safe?
The tool is free. No trial, no card, no watermark, and no daily limit.
Because compression happens on your own device, your PDF is never uploaded to a server. That is useful when you are working with private or confidential documents like contracts, medical records, or ID scans.
Common uses
- Getting a scanned application under a portal's upload limit
- Shrinking a photo-heavy report so it sends as one email attachment
- Reducing a multi-page scan before archiving or sharing it
- Making a large brochure or portfolio quicker to download
Frequently asked questions
Is this Compress PDF tool free?
Yes. Compression is free, with no signup, no watermark, and no daily limit.
How does the compression work?
Each page is re-rendered as an optimized JPEG image at a resolution set by the level you choose, then the images are rebuilt into a new PDF. Because images are what make PDFs large, this shrinks scans and image-heavy files dramatically.
Will the text still be selectable after compressing?
No. Compressed pages are images, so text remains readable and printable but can no longer be selected, copied, or edited. Keep your original file if you need to edit it later.
Which compression level should I choose?
Balanced is right for most documents. Choose high quality when the PDF will be printed or read closely, and small file when you need the absolute smallest size, for example to fit an upload limit.
Why did my PDF not get smaller?
PDFs that are mostly text are already tiny, and re-rendering them as images would make them larger. The tool never produces a file bigger than your original, so in that case it tells you the PDF is already compact instead of offering a worse file.
Is my file uploaded anywhere?
No. Compression runs entirely in your browser, so your PDF stays on your device and is never sent to a server.
Can I compress a password-protected PDF?
Not while it is locked. Remove the password first by opening the PDF and saving an unprotected copy, then compress that copy.
Is there another way to make a PDF smaller?
Yes. If you only need part of the document, extracting just those pages often shrinks it more than compression can. Use our Split PDF tool to pull out a page range into a new, smaller file.
Does it work on Mac and Windows?
Yes. It runs in any browser, so it works on Mac, Windows, Linux, and mobile without any install.
Read more: Why Your PDF Is So Large and How to Reduce PDF File Size for Email and Upload Limits.
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