Calqu Search tools
KR EN
Image

PDF Compressor

Reduce PDF file size — strong and safe modes.

Files never leave your device · Processed in your browser

Original kept — only the internal structure is re-saved. Text and layout stay exactly the same; savings may be smaller.

Compression mode
0.60
What is this?

Compresses a PDF entirely in your browser. Strong compression re-encodes each page as an image for big savings; Safe compression re-saves the internal structure only, keeping text and layout untouched. No upload needed — results appear instantly.

How to use it

Pick or drop one PDF file to see its page count and size. Choose a compression mode (strong/safe) on the right; in strong mode, adjusting quality and resolution (DPI) refreshes the preview on the left automatically. Click Compress → when ready.

Privacy & safety

Reading, rendering, compressing and downloading all happen entirely in your browser — files are never uploaded or stored on a server. Password-protected PDFs aren't supported; remove the password first.

Technology used

Document manipulation uses pdf-lib (MIT license); page rendering/preview uses pdf.js (Apache-2.0, Mozilla). Both libraries run from a local bundle on this site — no external CDN calls.

FAQ

How does PDF compression work here?
Everything happens in your browser. Strong compression redraws each page as a lower-quality JPEG image; Safe compression keeps page content as-is and only re-saves the PDF's internal structure to trim overhead.
What's the difference between Strong and Safe?
Strong compression can shrink files a lot, but pages become images, so text can no longer be selected, copied, or searched. Safe compression keeps the original text and layout intact, with smaller savings.
Does Strong compression remove selectable/copyable text?
Yes. Strong compression re-encodes pages as images, so the resulting PDF no longer supports text selection, copying, or search. Use Safe compression if you need to keep the original text.
What technology powers this tool?
Document manipulation uses pdf-lib (MIT license); page rendering and preview use pdf.js (Apache-2.0, Mozilla). Both libraries run from a local bundle in your browser and never call an external server.
Is my PDF uploaded to a server?
No. Reading, rendering, compressing and downloading all happen in your browser only — nothing is sent or stored on a server.
Can I compress a password-protected PDF?
No, decryption isn't supported. Please remove the password from the PDF first and try again.

Related tools

Image Compressor Reduce image file size while keeping quality. QR Code Generator Turn a URL or text into a QR code instantly. Data Converter (JSON/CSV/Table) Convert & clean JSON, CSV, Excel, tables, SQL and 30+ formats.