Custom Modify Headers

Modify request/response headers per URL pattern, managed entirely from the toolbar popup.

Custom Modify Headers lets you add, edit, and reorder rules that modify HTTP request and response headers for any site you choose — all managed from a single toolbar popup. Features: • Add or modify request/response headers per rule • Scope rules with URL patterns or regex • Enable/disable individual rules, drag to reorder priority • "Solo" mode to isolate and test a single rule • Per-rule notes to keep track of what each rule does • Toolbar badge shows how many rules are currently active • Full English / Korean interface Privacy: This extension does not collect, transmit, or sell any data. All rules are stored locally in your browser using chrome.storage.local — never synced to an account, never sent to any server. There is no analytics, no telemetry, and no remote code execution. Privacy policy: https://alb3it.github.io/modify-header/ Built on Manifest V3's declarativeNetRequest API for reliable, efficient header rewriting.