Professional Tier
HeaderGuard Pro
Modify HTTP request and response headers, spoof User-Agent strings and keep Sec-CH-UA client hints consistent. Manifest V3, fully local.
Coming soon to the Chrome Web Store
Privacy & data
£29/yr · £4.99/mo · £49 Lifetime
Why this exists: header tools tend to ask for broad access up front and keep more state than they need. HeaderGuard Pro is built for Manifest V3, requests host access per site rather than for everything, and keeps every rule in local storage — no telemetry, no account.
What it does
- Add, modify or remove request and response headers
- User-Agent presets for iPhone, Pixel, macOS, Windows and Googlebot
- Sec-CH-UA client hints stay synchronised with the header you set
- Up to 3 request rules free, unlimited rules and response headers on Pro
- Import legacy header profiles from JSON in one click
- Export your profiles to move between machines
- Per-domain auto-switching for different sites (Pro)
- 100% local processing with zero telemetry
Pricing
The free tier is permanent. Pro is £29/yr billed annually, or £4.99/mo month to month, or £49 Lifetime once. Cancel any time.
Questions
- Does it phone home with my headers?
- No. Rules are stored in local extension storage and applied by the browser. There is no server component.
- Can I import my old ModHeader profiles?
- Yes. Export them as JSON and use the built-in importer.
- Why does it need host permission?
- Header rules only apply to sites you explicitly enable. The permission is requested per domain, not up front.