How much smaller will my file get?

It depends almost entirely on what is inside. A PDF full of photographs or scans often drops by 50–90%, while one that is mostly text may barely change, because text and vector graphics are already compact. Nothing can shrink a file that has no redundancy left.

Will the text still be selectable and searchable?

Yes. Compression targets embedded images; text, fonts and vector artwork are left as they are, so you can still select, search and copy text in the output.

Which quality level should I choose?

Start in the middle. Use a lower quality for documents you only need to read on screen, and a higher one for anything that will be printed or contains fine detail such as maps or diagrams.

My file barely shrank. What else can I try?

Check whether it is already optimised, then try the Remove Images route if the pictures are decorative rather than essential. Scanned documents sometimes shrink far more after being converted to images at a lower DPI.

Compress PDF

Shrink a PDF's file size with selectable quality levels.

Processed locally in your browser — files never leave your device

What Compress PDF does

Most oversized PDFs are large because of the images inside them, so compression works by re-encoding those images at a lower resolution and quality. Pick a level, and you can compare the result against the original size before deciding to keep it.

How it works

The tool inspects your PDF for embedded images — photographs, scans, logos — which in a typical oversized document account for almost all of the bytes. Each image is decoded, scaled down if its resolution is higher than the chosen quality level needs, and re-encoded with stronger JPEG compression.

Text, fonts and vector graphics are left untouched: they are already compact and recompressing them would gain almost nothing while risking visible damage. The rebuilt document is then written out, and you see the old and new sizes side by side so you can judge whether the trade-off is worth keeping.

When to use it

A file exceeds an email attachment limit or a portal's upload cap.
A scanned document is tens of megabytes because the scanner used a needlessly high resolution.
You are archiving many documents and want them to take less space without becoming unreadable.
A report full of photographs needs to be shared quickly over a slow connection.

Advantages and limitations

Advantages

Selectable quality levels let you trade size against fidelity instead of accepting one fixed setting.
You see the size reduction before you commit — keep the result or try another level.
Text stays sharp, selectable and searchable, because only images are re-encoded.
Photograph-heavy and scanned documents routinely shrink by 50–90%.
No upload means even very large files start compressing immediately.

Limitations

Text-only PDFs barely shrink — there is little redundant data to remove.
Compression is lossy for images: fine detail in maps, diagrams or small print can soften at aggressive levels.
A file that has already been heavily compressed has little left to give; recompressing it mostly reduces quality, not size.
Encrypted files must be unlocked before they can be compressed.

Security and privacy

This tool runs entirely on your own device. The file you choose is read into your browser's memory, processed there by JavaScript, and returned to you as a download — no part of it is transmitted to our servers or anyone else's. When you close or reload the page, the browser discards that memory. We never see your document, cannot log it, and have nothing to delete afterwards. You can verify this yourself: open your browser's developer tools, switch to the Network tab, and process a file — you will see no request carrying your document.

The full detail of how this site handles data is in our Privacy Policy.

Supported files

Input: one standard PDF file (.pdf); scanned documents, exports and image-heavy reports benefit most. Encrypted PDFs must be unlocked first. Output: a compressed .pdf with the same pages and text, and re-encoded images.

How to use Compress PDF, step by step

Upload the PDF you want to shrink.
Choose a quality level — start in the middle if you are unsure.
Click Compress and wait a moment while images are re-encoded on your device.
Compare the new file size against the original shown on screen.
Happy with it? Download. Not small enough, or too soft? Pick another level and run it again from the original.

Frequently asked questions

How much smaller will my file get?: It depends almost entirely on what is inside. A PDF full of photographs or scans often drops by 50–90%, while one that is mostly text may barely change, because text and vector graphics are already compact. Nothing can shrink a file that has no redundancy left.
Will the text still be selectable and searchable?: Yes. Compression targets embedded images; text, fonts and vector artwork are left as they are, so you can still select, search and copy text in the output.
Which quality level should I choose?: Start in the middle. Use a lower quality for documents you only need to read on screen, and a higher one for anything that will be printed or contains fine detail such as maps or diagrams.
My file barely shrank. What else can I try?: Check whether it is already optimised, then try the Remove Images route if the pictures are decorative rather than essential. Scanned documents sometimes shrink far more after being converted to images at a lower DPI.