Flex Header
A lightweight yet powerful extension to modify http request headers
View on GitHubMade for
However you use HTTP Headers in your day to day life, Flex Headers is here to make your life easier.
Built by someone who uses HTTP Headers every day, this extension is full of useful features to make modifying headers stress-free
Features
Everything you need to manage HTTP headers day to day, from quick one-off tweaks to keeping a whole team's setup in sync.
Unlimited Pages
Easily separate different collections of headers by whatever you need, this could be by environment, by combination of settings or even a page for each of your projects!
Pages can also be enabled in the background so that you dont need to have it selected to be applied, allowing you to freely navigate between pages without having to worry about which headers are being applied
Smart Filters
Filter pages to only apply headers to certain requests, using either simple URL pattern matching or full regex, matched against the URL, domain or query string
Combine include and exclude filters on the same page to scope headers precisely, excludes always take priority so you can carve out exceptions without extra pages
Import and Export
Easily export individual or multiple pages to share with your team or to backup your settings. Send a file to your team and they can import it with a single click
Already using ModHeader? Import your existing export straight in and FlexHeader will map it across, including a summary of anything that needs a second look
Cross-Device Sync
Opt in to sync and your pages, headers and filters follow you between machines automatically via Chrome sync storage
A merge-and-tombstone system reconciles changes made on different devices, so edits never silently overwrite each other and deleted pages stay deleted
Undo / Redo History
Turn on history tracking to step backwards and forwards through edits to your headers, filters and pages
Handy for quickly experimenting with settings, safe in the knowledge you can always jump back to where you started
Pause Pages
Temporarily pause a page as a hard override, instantly switching off every header and filter on it without deleting or disabling anything individually
Flip it back on and everything picks up exactly where it left off, ideal for quickly ruling headers in or out while debugging
Flexible Sorting
Sort the headers on a page by name, value or comment, or group enabled headers above disabled ones with a single click
Keeps large pages of headers readable and easy to scan as your list of rules grows
Light & Dark Mode
FlexHeader looks right at home whether you're in a bright browser theme or working late in the dark, with every screen designed for both
Cross-Browser
Built with WXT so the same extension ships for Chrome and Firefox, with a native Safari app extension in the works too