Best Compress PDF - 100% local Alternatives in 2026

About Compress PDF - 100% local

Compress PDF files right inside your browser. Everything runs on your own machine - no uploads, no accounts, no servers, no tracking. Your files stay private at all times. Three one-click modes: Basic - Light cleanup with the original quality preserved. Good for files that are already well-optimised; gives a small size reduction without touching images. Balance - Recommended for most files. Re-compresses images with sensible quality settings to reduce file size noticeably while keeping text and pictures clear. Extreme - The strongest compression. Smaller file size with images that look slightly softer. Best for sharing or archiving when size matters most. How to use: 1. Click the extension icon and choose "Open compressor", or open the side panel and drag a PDF in. 2. Pick a mode (Basic, Balance, or Extreme). 3. Click Compress, then download the smaller PDF. When you are already viewing a PDF in a tab whose URL ends in .pdf, you can also click the extension icon and use "Compress this PDF" to skip the drag-and-drop step. Why local matters: - No upload limits - the file size cap is only your computer's memory. - Confidential documents (contracts, invoices, ID scans, medical records) never leave the browser. - Works offline once installed. - No account required. What the modes preserve: - Selectable, copy-paste text in every mode. - Annotations, form fields, bookmarks, and document outline. - Embedded fonts and the original page count. Permissions explained: - "activeTab" and "scripting" are used only when you click the extension on a PDF tab, to read that single tab's PDF bytes. We never access other tabs. The extension supports English and Vietnamese, and follows your browser language automatically. You can switch languages from the toggle inside the extension.