Tamper Chrome is a Chrome extension that allows you to modify HTTP requests

google/tamperchrome -- GitHub

Tamper Chrome is a Chrome extension that allows you to modify HTTP requests on the fly and aid on web security testing. Tamper Chrome works across all operating systems (including Chrome OS).

• Block / Reroute Requests: block or redirect a request from the browser
• Request Headers: drop, modify or add new headers.
• Response Headers: drop, modify or add new headers.
• Monitor PostMessages
• Monitor Reflected XSS
• Replay Requests (Experimental)