Why aren’t rules applying?

Scope or timing issues can prevent rules from firing. Prefer MV3 DNR with explicit URL patterns.

Is there a more reliable option?

Yes. Use a lightweight MV3 header editor focused on fast, predictable request header edits.

ModHeader Rules Not Applying? Try a Lightweight Alternative

Switch to a fast, MV3‑native header editor with clear scope and reliable application.

TL;DR: Rule scope or ordering can prevent headers from firing in some tools. VibeHeader focuses on fast request header edits and client‑side share links.

Explore the alternative Install for Chrome Manual install

Product UI with slogan: Stop Copy‑Pasting Headers, Share & use with 1‑click

Troubleshooting basics

Verify the URL pattern matches the target requests
Confirm the rule order and whether it overwrites/append
Check DevTools → Network for the effective headers