How to get your ModHeader profiles back after it was removed

ModHeader was removed from the Chrome Web Store and Edge Add-ons in July 2026. If your browser turned it off, the Export button went with it. Your profiles are still on your disk, and here is how to get them out.

Don't click "Remove" on ModHeader yet. While it's only turned off, Chrome keeps its data. Removing the extension deletes its storage folder, and your profiles with it.

What happened

Microsoft pulled ModHeader from Edge Add-ons on July 3, 2026 and Google from the Chrome Web Store on July 10. Version 7.0.18 contained a dormant collector for visited domains and pinged a third-party server on install and update (The Hacker News has the details). The collector reportedly never switched on, but the listings are gone, and Chrome turned the extension off for many people.

Where your profiles are

Chrome keeps every extension's chrome.storage.local in a LevelDB folder under your browser profile. ModHeader's id is idgpnmonknjnojddfkpgkljpfnnfcklj in Chrome (opgbiafapkbbnbnjcdomjaghbckfkglc in Edge), and it keeps everything under one key, profiles.

Windows, Chrome

%LOCALAPPDATA%\Google\Chrome\User Data\Default\Local Extension Settings\idgpnmonknjnojddfkpgkljpfnnfcklj

Windows, Edge

%LOCALAPPDATA%\Microsoft\Edge\User Data\Default\Local Extension Settings\opgbiafapkbbnbnjcdomjaghbckfkglc

macOS, Chrome

~/Library/Application Support/Google/Chrome/Default/Local Extension Settings/idgpnmonknjnojddfkpgkljpfnnfcklj

Linux, Chrome

~/.config/google-chrome/Default/Local Extension Settings/idgpnmonknjnojddfkpgkljpfnnfcklj

Several Chrome profiles? Open chrome://version in the one where you used ModHeader and use its "Profile Path" instead of …/Default. Copy the folder somewhere safe before anything else.

Option 1: read it in the browser

This is why I added a "Move from ModHeader" page to Headerwise, a free and open source header editor. You pick that folder and the page reads the LevelDB files right there, with nothing uploaded. Headers, URL filters, site, type and method filters, URL replacements and cookie rules come over, and the profile you had selected stays on. The extension can't make network requests at all, which you can check in its manifest.

Option 2: a command line tool

Requestly published a small CLI that finds the folder and writes the same JSON file ModHeader's own export would have. It needs Node.js 20 or newer:

npx @requestly/modheader-export-backup

The file it writes works with any tool that imports ModHeader JSON, Headerwise included ("Import JSON" in the popup).

Option 3: by hand

Copy the folder, open the copy with any LevelDB viewer, and read the value of the profiles key. It's plain JSON: an array of profiles with headers, respHeaders, urlFilters and so on.

Whatever you pick

Exports often hold Authorization tokens and session cookies. Treat the file like a password: don't commit it, and rotate anything sensitive you kept in ModHeader if you're unsure what happened to it. Once your profiles are safe, you can remove ModHeader.