Why did my PDF barely shrink, or come back unchanged?

Most of the size in a text-only PDF is fonts and text, which this tool does not rewrite. PDFs exported with "reduce file size" settings are also already compressed. When nothing smaller comes out you get the original back.

Can it compress password-protected PDFs?

No. Encrypted PDFs cannot be rewritten in the browser. Remove the password in your PDF reader first.

Are my PDF files uploaded to a server?

No. Your file is read into browser memory, processed on your own device, and released when you close the tab. Nothing is transmitted, stored, or logged at any stage.

Is there a file size limit?

There is no server-imposed cap because the work happens locally. Very large PDFs with hundreds of high-resolution images need a lot of memory and can be slow or fail on phones.

Updated for 2026 • 100% Free Online PDF Tool

Free PDF Compressor Online

This PDF compressor re-encodes the photos inside your PDF as JPEG and leaves the text, fonts and links alone, so the text stays selectable. For scans, a second mode turns each page into a JPEG at the resolution you choose; that shrinks harder but the text can no longer be selected or searched. It runs in your browser with pdf.js and pdf-lib, and if nothing smaller comes out you get your original back.

Select or drop your PDF

Processed in your browser with pdf.js and pdf-lib. Nothing is uploaded.

100% Client-Side Private Processing

Your files are processed locally on your own device. Zero server uploads, zero file storage, and zero tracking.

Zero Server Logs

How PDF Compression Works Here

Re-compress images (default): every embedded RGB or greyscale photo is decoded, optionally shrunk to a maximum size, and saved as JPEG at the quality you set. An image is only replaced if the new version is smaller. Text, vector graphics, fonts and links are untouched.
Uncompressed page content is also deflated, which is lossless.
Rasterise pages: renders every page to a JPEG at 72 to 200 DPI and rebuilds the PDF from those pictures. Use it for scanned documents. Text stops being text, so it cannot be selected, searched or read aloud.
What it cannot shrink: PDFs that are mostly text and fonts, already-optimised files, and images in CMYK or other print colour spaces, which are left as they are to avoid colour shifts.
Never larger: if the result is not smaller, the original is handed back and the page says so.

Step by step

How to COMPRESS PDF Files in 3 Steps

1
Upload your PDF
Drop the PDF into the compressor.
2
Pick a method and quality
Keep "Re-compress images" unless the PDF is a scan. Lower quality means a smaller file.
3
Download
Compare the before and after sizes, then save the PDF.

Common Questions

Frequently Asked Questions

Everything you need to know about the free online PDF compress tool.

Yes in the default "Re-compress images" mode, which only touches images. No in "Rasterise pages" mode, which turns every page into a picture; the page warns you before you use it.

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