Cache Killer Extension

A Chrome extension that disables browser cache to ensure pages always load fresh content from the server instead of using cached versions.

Features

• Toggle On/Off: Easy toggle functionality via extension popup (icon click)
• Multiple Operation Modes:
  • All Sites: Disables cache on all websites (default)
  • Include List: Only disables cache on specified domains
  • Exclude List: Disables cache on all sites except specified domains
• Domain Pattern Configuration: Add specific domains or wildcard patterns for targeted cache control
• Import/Export Domains: Import domain lists from text files or export current configuration (access from domain list configuration page)
• Advanced Options: Collapsible section with optional features
• Visual Indicators: Icon changes color and shows badge when enabled
• Badge Mode Indicator: Badge shows "ON(A)", "ON(I)", or "ON(E)" for All, Include, or Exclude mode
• Current Page Status in Popup: Popup displays if cache killer is active on the current tab, and why/why not
• Automatic Cache Prevention: Uses multiple methods to prevent caching:
  • Primary Method: Modifies HTTP request headers to add no-cache directives (always reliable)
  • Optional: Force cache clearing features (advanced option, configurable time ranges, wildcard handling)
• Domain-Specific Cache Clearing: Smart cache clearing that targets specific domains when possible

How It Works

The extension uses two main approaches to disable caching:

1. Header Modification (Primary method): Intercepts HTTP requests and adds cache-control headers:

   • Cache-Control: no-cache, no-store, must-revalidate
   • Pragma: no-cache
   • Expires: 0

2. Force Cache Clearing (Optional): When enabled in advanced settings:

   • Domain-specific clearing: Uses Chrome's origins API to clear cache for specific domains
   • Wildcard handling: Smart handling of wildcard patterns with user-configurable fallback
   • Configurable time ranges: Expert settings allow customization of periodic (1-60 minutes) and manual (1-168 hours) cache clearing time ranges
   • Fallback behavior: For wildcard patterns, can either skip clearing or clear all cache (user choice)

Installation

Method 1: Load as Unpacked Extension (Development)

1. Open Chrome and navigate to chrome://extensions/
2. Enable "Developer mode" in the top right corner
3. Click "Load unpacked"
4. Select the folder containing this extension
5. The extension should now appear in your extensions list

Method 2: Pack and Install

1. In Chrome extensions page (chrome://extensions/), click "Pack extension"
2. Select the extension folder as the root directory
3. Click "Pack Extension" to create a .crx file
4. Install the .crx file by dragging it to the extensions page

Alternatively, install from the Chrome Web Store
(Note: The Chrome Web Store version may not always have the latest updates.)

Usage

1. Click the extension icon in the toolbar to toggle on/off
2. Use the popup interface:
   • Toggle the main switch to enable/disable cache killing
   • Select operation mode:
     • All Sites: Works on every website
     • Include List: Only works on domains you specify
     • Exclude List: Works on all sites except domains you specify
   • Click "Configure Domain List" to add/remove domains and patterns
   • Advanced Cache Options (click to expand):
     • Enable "Periodic cache clearing" for automatic force cache clearing
     • Enable "Clear all cache for wildcards" to change wildcard behavior
     • Manual "Clear Cache Now" button
     • Expert Settings (double-click to access): Configure cache clearing time ranges and reset all settings
   • All user preferences are stored locally and persist across browser sessions
3. Domain Configuration:
   • Add specific domains: example.com, localhost
   • Use wildcards for subdomains: *.google.com, *.wikipedia.org
   • Local development: localhost, *.local
   • Import/Export: Import domain lists from text files or export current configuration
   • Validation: All domains are validated against RFC 1035 standards during import/manual entry
4. Visual feedback:
   • When enabled: Icon turns red with mode badge ("ON(A)", "ON(I)", or "ON(E)")
   • When disabled: Icon is gray with no badge
   • Domain count shown in popup
   • The popup will tell you if the extension is affecting the current page

Import/Export Domains

The domain configuration supports importing and exporting domain lists:

Export

• Click "Export to File" in the domain configuration window
• Downloads a cache-killer-domains.txt file with one domain per line
• Simple text format for easy editing and backup

Import

• Click "Import from File" to select a text file
• Supports one domain per line format
• Lines starting with # are treated as comments and ignored
• Choose to either replace existing domains or merge with current list
• Invalid domains are automatically filtered out with RFC-based validation
• Shows summary of imported vs. rejected entries

Example Import File Format

# Development domains
localhost
127.0.0.1
192.168.1.100
dev.local

# Production sites
example.com
*.example.com
google.com

# Social media
*.facebook.com
*.twitter.com

Permissions Required

• browsingData: To clear browser cache
• storage: To save extension settings (enabled state, mode, domain list)
• declarativeNetRequest: To modify HTTP headers
• tabs: To create domain configuration window
• <all_urls>: To work on all websites

Files Structure

├── README.md            # This file
extension/
├── manifest.json          # Extension manifest (Chrome Extension Manifest V3)
├── background.js          # Service worker for background operations
├── popup.html            # Extension popup UI
├── popup.js              # Popup functionality
├── domain-config.html    # Domain configuration interface
├── domain-config.js      # Domain configuration functionality
└── icons/                # Extension icons
    ├── icon16.png
    ├── icon48.png
    ├── icon128.png
    ├── icon16-active.png
    └── icon48-active.png
    └── icon128-active.png

Technical Details

Manifest V3 Compatibility

This extension is built using Chrome Extension Manifest V3, which means:

• Uses service worker instead of background pages
• Uses chrome.action instead of chrome.browserAction
• Follows modern extension security practices

Cache Prevention Methods

1. Smart Domain Filtering: The extension now supports three modes:

   • All Sites Mode: Works on every website (original behavior)
   • Include List Mode: Only applies cache killing to domains matching your configured patterns
   • Exclude List Mode: Applies cache killing to all sites except those matching your patterns

2. Domain Pattern Matching: Uses wildcard patterns for flexible domain matching:

   • *.example.com matches all subdomains of example.com (mail.example.com, api.example.com) but not example.com itself
   • example.com matches exactly example.com
   • localhost matches the localhost domain

3. Request Header Modification: Intercepts HTTP requests and modifies headers to prevent caching (domain-specific, always works)

4. Smart Cache Clearing: When enabled, uses Chrome's browsingData API with origins parameter for domain-specific cache data clearing

5. Configurable Time Ranges: Expert settings allow customization of cache clearing time ranges:

   • Periodic clearing: 1-60 minutes (default: 5 minutes)
   • Manual clearing: 1-168 hours (default: 24 hours)

6. Wildcard Handling: Intelligent handling of wildcard patterns with user-configurable fallback behavior

7. RFC-Based Domain Validation: All domain entries validated against RFC 1035 standards

8. Badge and Popup Status Logic:

   • The badge text updates to reflect the current mode (All, Include, Exclude)
   • The popup queries the background script to determine if the current page is affected and displays a status message

Troubleshooting

• Extension doesn't work: Make sure you've granted all required permissions
• Still seeing cached content:
  • Try disabling and re-enabling the extension, then refresh the page
  • Check if the current page matches your domain configuration (Include/Exclude mode)
  • Use "Clear Cache Now" button in advanced options for immediate cache clearing
• Wildcard patterns not working as expected:
  • Check the domain configuration page for wildcard usage examples
  • Enable "Clear all cache for wildcards" if you need aggressive cache clearing for wildcard patterns
• Import not working:
  • Ensure text file uses one domain per line format
  • Check that domains follow valid format (no invalid characters, proper structure)
  • Lines starting with # are treated as comments
• Performance issues: Reduce periodic cache clearing frequency in expert settings or disable it entirely

Development

To modify or extend this extension:

1. Edit the relevant files (background.js, popup.js, etc.)
2. Go to chrome://extensions/
3. Click the refresh icon on the extension card to reload it
4. Test your changes

License

See LICENSE.

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Author

• Jaewoo Jeon @thejjw

If you find this extension helpful, consider supporting its development via GitHub Sponsors (one-time or monthly), or Buy Me a Coffee: