PDF Compressor
Tiny & Fast — 100% In Your Browser
Compress PDF files instantly with up to 90% size reduction. No uploads, no cloud, no servers — everything runs locally on your device, completely offline.
Built for Speed, Privacy & Control
Everything runs in your browser — your files never leave your device.
100% Private & Offline
Files are processed entirely in your browser using Web Workers. Nothing is uploaded to any server — ever. Disconnect from the internet and it still works.
4 Compression Modes
Choose from Fast (20–35%), Balanced (40–60%), High (60–80%), or Max (75–90%) compression — or set a custom target file size.
Smart PDF Analysis
Automatically analyses each PDF's content — images, text, fonts, page count — and recommends the ideal compression mode before you begin.
Batch Processing
Compress multiple PDFs in one go. Add files to the queue, run them simultaneously, and download individually or as a ZIP archive.
Compression History
Keeps a full log of all your compression sessions — original size, compressed size, savings percentage — stored locally on your device.
Target File Size
Set an exact target file size and the engine iterates automatically until it gets as close as possible — with a feasibility warning if the target can't be reached.
Pick Your Level
The smart analyser recommends the right mode automatically — or you choose.
Light pass — ideal for text-heavy PDFs that need minimal size reduction while preserving maximum quality.
Best for mixed documents with both images and text. Good quality-to-size ratio for general use.
Aggressive image downscaling. Ideal for image-heavy PDFs like scanned documents or photo portfolios.
Maximum possible compression. For smallest file size when image quality is not a priority.
Zero Server Contact
PDF Compressor – Tiny & Fast uses a Web Worker running in a sandboxed background thread. Your PDF files are read directly from your device, compressed using the pdf-lib engine with GZIP + JPEG scaling, and returned to you — without a single byte leaving your browser. You can compress files on Airplane Mode and it works identically.
Read the full Privacy Policy →Frequently Asked Questions
- Are my PDF files uploaded to your servers?
- No — never. Every compression operation runs entirely inside your browser using a Web Worker. Your files do not leave your device at any point. There are no servers involved in the compression process.
- Does it work without an internet connection?
- Yes. Once the app has loaded in your browser (which requires a one-time internet connection), you can switch to Airplane Mode and compress PDFs indefinitely. Everything runs on your local device CPU.
- How much can it compress a PDF?
- Up to 90% in Max mode for image-heavy PDFs. Results vary by content type — a text-only PDF may only reduce by 20–30%, while a scanned photo document can shrink dramatically. The smart analyser estimates the reduction before you compress.
- Can I compress multiple PDFs at once?
- Yes. Add multiple files to the queue and they'll be processed simultaneously. Download each compressed file individually or export all as a ZIP archive in one click.
- What is the maximum file size it can handle?
- There's no hard limit set by the app. The practical limit is your device's available RAM. Most modern devices handle PDFs up to several hundred megabytes without issues. Very large files (500MB+) may take longer on lower-end devices.
- Is PDF Compressor free to use?
- Yes — completely free, with no account required, no file limits, no watermarks, and no sign-up. Open the app and start compressing immediately.
- What technology powers the compression?
- The compression engine is built on pdf-lib (an open-source PDF manipulation library) running inside a Web Worker for sandboxed thread isolation. It applies GZIP compression and JPEG image downscaling to reduce file size. The engine is licensed under Apache-2.0.
Compress Your First PDF Now
Free, private, instant — no account, no uploads, no limits.