Compress PDF Files
Reduce PDF file size by downsampling high-DPI raster images and re-encoding with in-browser WebAssembly. Choose preset levels or an exact target size with zero uploads.
Drag & drop a PDF file here, or browse
Never uploads your documents. Fast client-side image downscaling.
document.pdf
Reading document...
Balanced: Downsamples raster images to 110 DPI with 70% JPEG quality. Balances small file size with sharp, clean readability.
Advanced Settings (Custom DPI & Mode)
Leave empty to use preset resolution.
Manual JPEG encode quality (10 - 100%).
Compressing document...
Re-encoding page raster streams
PDF Compressed Successfully!
Processed in seconds • zero bytes uploaded
The smartest way to reduce PDF file size
Fast Compression
Downsample high-DPI images and re-encode PDF streams in seconds.
Zero Server Uploads
All processing happens 100% on your machine with WebAssembly.
Custom Controls
Choose balanced presets or an exact target size for email and web.
How to Compress PDF Documents in Browser
Follow these 4 simple steps to process your files directly on your device with 100% privacy.
Select or Drop PDF
Choose your PDF document from your device. The file is read directly into local browser memory without uploading to any remote server.
Choose Level or Target Size
Pick 'Balanced (110 DPI)', 'Max Compression (72 DPI)', 'Keep Text (Lossless)', or enter a precise target KB (e.g. 200 KB) for application portals.
Process Locally
DocuShrink's client-side WebAssembly engine recompresses embedded streams and downsamples images right inside your browser.
Download & Chain
Save your optimized PDF instantly with zero server latency, or click to Split, Merge, or Sign without re-selecting.
Supported Formats & Processing Limits
Built for Everyday Productivity
Compress PDF to 200 KB or 100 KB for Government & Job Portals
Many job applications, university portals, and government websites (USCIS, DV Lottery, UPSC) enforce strict 100 KB – 500 KB limits. Use our 'Custom Target Size' slider to hit the exact target KB without trial and error.
Scanned vs Digital PDF: Choosing the Right Compression Mode
For scanned paper contracts, use 'Smart Page Downsampler' to aggressively shrink raster pages. For digital reports with selectable text and vector diagrams, use 'Keep Text' to preserve crisp fonts and copy-paste capability.
Understanding PDF Compression Algorithms: FlateDecode & DCT Streams
Learn how in-browser downsampling, DPI ratios, and JPEG stream compression work to reach strict 100 KB and 200 KB submission limits without cloud transmission.
Frequently Asked Questions
Everything you need to know about browser processing, file safety, and format capabilities.
Does compressing a PDF delete my text or searchable words?
If you choose 'Keep Text (Lossless)', all text layers, fonts, bookmarks, and links remain untouched. If you choose 'Smart Page Downsampler', pages are converted to high-efficiency JPEG images, making text non-selectable unless OCR is re-applied.
How can I reduce a PDF file size to under 200 KB or 100 KB?
Select the 'Target Size' option and set your target slider to 200 KB. Our adaptive compression algorithm automatically calculates the optimal DPI and JPEG quality stop to hit your target file size.
Is my PDF uploaded to any external server?
Never. DocuShrink operates entirely on your device via client-side WebAssembly. You can disconnect your internet or turn on Airplane Mode, and the compression will still execute normally.
Why is my already-compressed PDF not getting any smaller?
If a PDF already contains heavily compressed JPEG images or lacks raster graphics (e.g. pure vector text), further compression yields diminishing returns. DocuShrink detects this and displays an 'Already Optimized' notification rather than returning a larger file.
Can I compress password-protected PDF files?
Yes! Enter your password to unlock the document locally in your browser memory, after which you can adjust compression settings and export the optimized file.