🗜️ Compress PDF
Reduce PDF file size with adjustable quality levels
✓ Free Forever · ✓ No Signup · ✓ No Upload · ✓ Works Offline
🔒 Your documents never leave your device. All processing happens locally in your browser using pdf-lib + browser JPEG re-encoding. No upload, no server, no tracking.
Features
- Three Compression Levels — Choose light, medium, or aggressive compression to balance file size and quality.
- Size Comparison — See original vs. compressed file size and the percentage saved.
- 100% Private — Compression runs entirely in your browser. No upload, no server.
- Fast Processing — Optimized compression algorithms deliver results in seconds.
How It Works
- Upload your PDF — Drop a PDF file you want to compress.
- Select compression level — Choose light (best quality), medium (balanced), or aggressive (smallest file).
- Download compressed PDF — Review the size savings and download the compressed file.
Use Cases
- Reduce PDF size for email attachments
- Optimize PDFs for faster web downloads
- Save storage space on cloud drives
- Shrink PDFs for mobile viewing
Frequently Asked Questions
How much can the file size be reduced?
It depends on what's inside. Photos and scans stored as JPEG shrink the most — often 50-80% at Medium or Aggressive. A text-only PDF has little to remove and may not get smaller at all; then the page says so and gives you nothing to download, instead of a 'compressed' file that's bigger.
Which images get compressed?
JPEG photos — what cameras, phones and most colour scanners produce. They're re-saved smaller and scaled down to 2500 px (Medium) or 1600 px (Aggressive) on the long side. PNG-style images, JPEG 2000, CMYK photos and black-and-white fax-style scans are left untouched, and so are text, fonts, links and form fields.
Does compression affect text quality?
No. Text remains sharp and searchable. Compression primarily targets embedded images.
Is there a file size limit?
No hard limit since processing is local. Very large PDFs (100MB+) may take longer depending on your device.
Notes from Milo 🐨
Confession: this compressor never touched the photos inside a PDF, which is what makes PDFs big — it just re-saved the file, and if that came out bigger it still offered it as "compressed". Now Medium and Aggressive really re-save the JPEG photos smaller (my test scan went from 9.7 MB to 1.9 MB), while text, links and form fields stay exactly as they were. If a level can't make your file smaller, the page says so and gives you nothing to download. Aggressive also no longer deletes your links and comments. Phone PDFs without a proper file type load, and password-protected files get a link to Unlock PDF.
From the blog
- 📖 How to Compress a PDF to Email It (Without Wrecking Quality) — Shrink a too-big PDF so it fits in an email, right in your browser with no upload. Why PDFs balloon, what compresses well, and honest tool picks.
Related Tools
- 📑 Merge PDF — Merge multiple PDF files into a single document — all in your browser
- ✂️ Split PDF — Split a PDF into separate files or extract specific pages
- 📦 Compress Image — Reduce file size without losing quality — all in your browser
- 🔄 Rotate PDF — Fix sideways scans or flip specific pages — entirely in your browser
💬 Bug, idea, or just to say hi? Tell Milo 🐨 · [email protected]