Compress PDF
OptimizeShrink PDF file size by re-encoding embedded images. Pick a quality level and get a smaller file in seconds.
How to use Compress PDF
- Open this page in any modern web browser — no download or installation required.
- Click Add file or drag and drop your PDF onto the drop zone.
- Adjust the available settings to fit your needs.
- Click the action button and save the processed file — the result is ready instantly.
Files never leave your browser. No upload to any server.
Processing runs locally on your device. No queues, no waiting.
No signup, no watermarks, no limits. Use as many times as you like.
Why use Compress PDF on PDF Modern?
PDF Modern’s compress pdf tool processes your file entirely within your web browser using modern WebAssembly technology. Unlike traditional online PDF services that require uploading your documents to remote servers, your files never leave your device — ensuring complete privacy and security. Processing happens at the full speed of your CPU, not limited by upload or download bandwidth, so even large files are handled in seconds. There are no file-size restrictions, no daily usage caps, no watermarks on output, and no account creation needed. It is a fully free, open tool built for everyday document workflows at home, school or the office.
Frequently asked questions
How does this compressor work?
It rasterises each page to an image, re-encodes it as JPG at the chosen quality, and rebuilds a smaller PDF — fully in your browser.
Will text remain selectable?
Because pages are re-encoded as images, selectable text is lost. For text-heavy PDFs prefer a server-side tool that recompresses image streams only.
Is the file uploaded?
No. All processing stays on your device.