RequestKit

RequestKit is a Manifest V3 Chrome extension for setting custom request headers per site or across all HTTP and HTTPS sites.

• Detects the current tab's site automatically.
• Offers two mutually exclusive modes: Per site and All sites.
• Keeps an independent header profile for each hostname in Per site mode.
• Uses one global header profile in All sites mode.
• Provides a compact site manager for searching, filtering, and editing every profile.
• Supports profile-level and rule-level switches without losing either state.
• Adds, edits, deletes, enables, and disables header rules.
• Allows duplicate header names; the last enabled matching rule takes precedence.
• Applies saved changes to new matching requests with Chrome's declarativeNetRequest API.
• Stores configuration locally in chrome.storage.local.

npm install
npm run dev

The browser preview includes neutral sample rules so the interface and interactions can be reviewed without installing the extension. Those samples are not created in the installed extension.

npm run build

Then open chrome://extensions:

1. Turn on Developer mode.
2. Select Load unpacked.
3. Choose the project's dist directory.

RequestKit only affects requests made after an enabled rule is applied. Completed requests are never changed.

In Per site mode, a site profile applies only when a request's destination hostname exactly matches the configured hostname. Ports and paths do not change that match. Subdomains and third-party destinations need their own profiles. Because RequestKit stores these settings as persistent dynamic rules, they also cover the first navigation to a configured site after Chrome restarts.

In All sites mode, the global profile applies to every HTTP and HTTPS destination. Switching modes preserves the global profile and every site profile; it changes only which scope is active.

Each profile has its own profile-level switch. Turning off a site profile affects only that hostname. Turning off the global profile affects only All sites mode. In both cases, the enabled states of individual header rules are preserved for the next time that profile is turned on.

Chrome allows up to 1,000 enabled regex-based site profiles at once. RequestKit rejects and rolls back a change that would exceed that limit, leaving the previously applied rules intact.

Header rules and values remain in this browser's chrome.storage.local. RequestKit has no account system, analytics, telemetry, advertising, remote code, or developer-operated server. See the Privacy Policy for details.