HeaderSwap guides for local header testing
Updated October 2026 · v1.2.0
Modify request headers in Chrome, test CORS locally, set a User-Agent, add a bearer token, and compare HeaderSwap with ModHeader and Requestly.
Part of HeaderSwap for HTTP Headers.
ModHeader alternative
When to keep ModHeader, when HeaderSwap is a practical MV3 alternative, and how to import an export.
Requestly comparison
Requestly covers mocks, scripts, and redirects as well as headers. HeaderSwap stays on headers and redirects. Pick the smaller tool when that is the whole job.
Test CORS locally
How browser CORS works, how to confirm it in DevTools, and how a local Allow CORS header override differs from a real server fix.
Override User-Agent
Change the User-Agent from Chrome DevTools or with a HeaderSwap rule, and what a spoofed User-Agent does not change.
Add a bearer token
Send an Authorization bearer token on local API calls, keep it out of git, and let a temporary token expire.