URL Query Parameter Appender

Automatically append query parameters to URLs based on hostname

URL Query Parameter Appender is a practical and efficient browser extension designed to automate the process of adding custom query parameters to URLs based on specified hostnames. This tool is especially useful for developers, marketers, testers, and power users who need to consistently apply parameters such as tracking codes, analytics tags, affiliate identifiers, or feature flags across multiple browsing sessions without manually editing URLs. By seamlessly integrating into your browsing experience, the extension ensures that every visit to specified domains automatically includes your defined query parameters, eliminating errors and saving time. The user interface is accessible via a compact, streamlined popup inspired by popular tools like ModHeader. You can easily create and manage mappings between hostnames and their appending query parameters. Simply click "+ Add mapping" at the bottom of the list, enter a hostname (for example "example.com") along with query parameters like "utm_source=extension&utm_campaign=promo," and your mapping is saved instantly. Input validation is built in to verify hostnames and parameter strings, providing immediate feedback to prevent mistakes. All your mappings are displayed in a clean, space-efficient list where each entry can be edited inline—just click on the hostname, parameters, or comment field to modify them, and changes are auto-saved as you type. Each mapping includes a checkbox to quickly enable or disable it without deleting, perfect for temporarily turning off certain parameters while keeping your configuration intact. Add optional comments to document what each mapping is used for, making it easy to remember the purpose of each configuration. Removing a mapping is just one click away with the delete button. A powerful feature is the ability to create multiple mappings for the same hostname. This allows you to organize different parameter sets separately—for example, one mapping for analytics tracking and another for A/B testing—and enable or disable them independently. When multiple mappings for the same hostname are enabled, their parameters are automatically merged. If the same parameter key appears in multiple enabled mappings, the value from the mapping added later in the list takes precedence. Entries that share a hostname with other entries are visually indicated with a colored border, making it easy to identify related configurations at a glance. Leveraging the declarativeNetRequest API, the extension performs its URL modifications quickly, securely, and at a network-request level inside the browser. This means URLs are altered before navigation happens, making the process robust and reliable even under complex browsing conditions. Further enhancing usability, your settings are stored in the browser's sync storage, enabling automatic synchronization across your devices and profiles where you are signed in. The extension has been developed with privacy as a foremost concern. It does not collect or inspect any personal browsing data, cookies, or page content. All data related to query parameter mappings remain on your device or within your browser sync account, giving you full control and transparency. Ideal for marketing link consistency, experimental A/B testing setups, affiliate marketing tracking, or toggling site features without cumbersome manual URL edits, URL Query Parameter Appender offers a clean, intuitive experience paired with powerful functional reliability. Its background service worker listens for changes and updates rules on the fly, ensuring that your custom parameters are always appended exactly as you desire without delay or interruption. Key Features: • Automated Query Parameter Appending: Ensure specified query parameters are automatically added to every URL you visit on selected hostnames. • Multiple Mappings per Hostname: Create multiple parameter sets for the same hostname and enable/disable them independently—enabled mappings are automatically merged. • Smart Parameter Merging: When multiple mappings for a hostname are enabled, parameters are merged with later mappings taking precedence for conflicting keys. • Visual Duplicate Indicators: Entries sharing a hostname are highlighted with a colored border for easy identification. • Enable/Disable Toggle: Quickly turn individual mappings on or off with a checkbox, without losing your configuration. • Inline Editing with Auto-Save: Click on any hostname, parameter, or comment field to edit it directly—changes save automatically as you type. • Comments for Documentation: Add optional comments to each mapping to remember what it's used for—great for organizing multiple configurations. • Intuitive Mapping Management: Add new mappings with the "+ Add mapping" button, or delete existing ones instantly with one click. • Compact Modern Interface: Clean, space-efficient design displays more mappings in less space, inspired by popular developer tools. • Robust Validation & Feedback: Built-in validation checks hostnames and query parameter syntax, providing real-time feedback. • Browser Sync Storage: Settings and mappings are securely stored and synchronized via browser sync, keeping your configurations consistent across devices. • Declarative Net Request Engine: Uses the high-performance declarativeNetRequest API for fast, reliable URL rewriting without manual intervention. • Instant Rule Updates: Any update you make to mappings is applied immediately, avoiding any lag or disruption. How It Works: 1. Install the URL Query Parameter Appender extension. 2. Click the extension icon to open the popup user interface. 3. Click "+ Add mapping" at the bottom to create a new mapping. 4. Enter a target hostname and the query parameters you want appended (e.g., key1=value1&key2=value2), optionally add a comment to document the mapping, then confirm. 5. Add multiple mappings for the same hostname if needed—each can be enabled/disabled independently, and enabled ones will be merged automatically. 6. Review your current mappings listed clearly in the popup—each showing a checkbox, hostname, parameters, and comment. Duplicate hostnames are indicated with a visual marker. 7. Edit any mapping inline by clicking on the hostname, parameters, or comment field; changes auto-save. 8. Use the checkbox to enable or disable individual mappings without deleting them. 9. Delete any mapping with the × button; changes take effect instantly. 10. Browse the web as usual; the extension automatically appends your specified parameters when navigating to matching hostnames. 11. Sync your settings across all signed-in browsers, ensuring your parameter appending rules travel with you. Privacy: No personal data collected. This extension only stores the query parameter mappings you provide locally and optionally in the browser's secure sync storage to perform its functions. It does not access or transmit any browsing history, cookies, or page contents.