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Preview of Custom Header Tailor

Custom Header Tailor by Anto

Override or add custom HTTP headers on requests and responses. Two lists (request/response), per-rule on/off toggle and optional URL match pattern. Rules are saved locally and persist across restarts. No data collection.

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Extension Metadata

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About this extension
Custom Headers lets you override or add HTTP headers on the browser's requests and responses.
Features
- Two separate sections: Request Headers and Response Headers.
- Add or remove header rows on the fly (name + value).
- Enable/disable toggle on every row.
- Optional per-row "URL match pattern" to limit a rule to specific sites (default: all URLs).
- Smart behaviour: if a header already exists, its value is replaced; otherwise it is added.
- Rules are stored locally and persist across browser restarts.
- Clean, minimal popup, localized in 12 languages.

Privacy
The extension does not collect, store remotely, or transmit any data. Every rule stays in your browser's local storage. Built entirely on the standard declarativeNetRequest API, with no external dependencies.
Open source (MPL-2.0): https://gitlab.com/mrdjtoto/mozilla-custom-headers
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Permissions and data

Required permissions:

  • Block content on any page

Optional permissions:

  • Access your data for all websites

Data collection:

  • The developer says this extension doesn't require data collection.
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More information
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Version
1.0.1
Size
41.76 KB
Last updated
22 days ago (Jul 1, 2026)
Related Categories
  • Web Development
License
Mozilla Public License 2.0
Version History
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