Compress PDF Online for Free
or drop files here
The images inside your PDF are re-encoded locally, so the text stays selectable and searchable. Your file never leaves your browser.
Three steps. Done in your browser.
Drop your PDF
Drag a PDF onto the zone or click to browse. No file size limit, all processing is local.
Choose a quality level
Light, Medium or Heavy, fine tune with the slider, or name a target size. Only the images are re-encoded, so your text stays text.
Save the result
Progress is shown as each image is processed, and you can cancel at any point. The compressed PDF saves straight to your device.
Choosing the right compression preset.
The preset controls how aggressively each PDF page is re-compressed. Lighter compression means larger files; stronger compression means smaller files with softer detail.
| Compression | Best for | Typical reduction |
|---|---|---|
| Light | Print, archive, client-facing reports | Typically 30–70% smaller |
| Medium | Email attachments, everyday sharing | Typically 60–90% smaller |
| Heavy | Internal notes, rough drafts | Typically 80–95% smaller |
Why compress a PDF?
PDF files balloon when they contain photographs, scans, or graphics-heavy slides. One scanned contract can hit 20+ MB, well above the limits most email providers allow.
Email attachments
Gmail, Outlook, and most providers cap attachments at 10–25 MB. Compress first and it sends without issues.
WhatsApp and messaging
Large files take minutes over mobile data. A compressed PDF sends in seconds and uses far less data.
University and government portals
Many submission systems enforce strict limits, often 5 MB or less. A compressed PDF almost always fits.
PDFs embedded on websites
Smaller PDFs load faster when embedded in a page, improving the experience for mobile visitors.
Cloud storage savings
Archiving large volumes of PDFs? Compression can cut your storage footprint by half or more.
Reports and presentations
Marketing decks and annual reports with embedded photos can be huge. Compress before sharing with clients or uploading to drives.
How it works under the hood.
Unlike most online compressors that upload your file to a remote server, our tool runs entirely inside your browser tab. When you drop a PDF, it uses PDF.js (Mozilla's open-source library) to render each page as a canvas element, then re-encodes every page as a compressed JPEG image before bundling the result into a new document using pdf-lib.
Your PDF never leaves your device. There is no upload, no server, and no risk of your confidential documents being stored or accessed by anyone else.
Your files never leave your browser.
Most online PDF tools upload your document to a server. This tool is architecturally different: your own CPU opens the PDF, re-encodes the images inside it, and writes the new file, all in a background worker. No server ever receives your document.
No network requests
Zero bytes of your file are transmitted over the network at any point during processing.
No account needed
No sign-in, no email, no tracking. Open the page, compress, and close.
Auto-cleared on close
Closing the tab wipes all file data from browser memory. Nothing persists.
Open source stack
Built on PDF.js and pdf-lib. Fully auditable, no proprietary black boxes.
Questions answered.
How much can I reduce my PDF size?
Will the text in my PDF still be selectable after compression?
Is there a file size limit?
Is my PDF file uploaded to a server?
Which quality setting should I choose?
Can I compress a password-protected PDF?
How long does compressing a large PDF take?
Does compressing reduce the resolution permanently?
More tools you might need.
Related Guides & Tutorials
Why Does My PDF Reader Freeze and Crash When Opening Large Architectural Blueprints? (CAD Fix)
Why do CAD and architectural PDF drawings freeze Adobe Reader and browser viewers? Find what makes a sheet heavy, change the viewer settings that help, and export lighter PDFs from AutoCAD.
How to Reduce PDF File Size While Keeping Vector Text 100% Sharp (Smart Compression)
Why some PDF compressors turn text into blurry pictures, where a PDF's size really comes from, and how to shrink only the images in Acrobat Pro, Mac Preview, Ghostscript or your browser.
Why Is My Scanned Document PDF Over 50MB for Only 3 Pages? (Fix Guide)
Why scanners turn a few pages into a 50 MB PDF, the resolution and color settings that fix it for future scans, and how to shrink the file you already have.