Rated 4 out of 5 stars

{Could you please add a privacy policy for this listing? Thank you.}

Works great. Even covers extra values according to this. http://browserspy.dk/browser.php

Rated 5 out of 5 stars

Works as intended.

This review is for a previous version of the add-on (59.0t52). 

Rated 5 out of 5 stars

Works well. Thanks! If only it had a github page it would be perfect, as we could check the code.

This review is for a previous version of the add-on (58.0t52). 

Rated 4 out of 5 stars

Will this add-on be converted to webextensions? Firefox will only allow webextensions starting with Firefox 57.

This is the rare user agent add-on that also spoofs js settings. Thank you.

This review is for a previous version of the add-on (54.0t52.2.1). 

11/15/2017: I've been able to implement it as a WebExtension, but some minor nice-to-have traditional features couldn't be implemented so far. If the bug i mentioned below is fixed, it might be easier to re-implement the traditional features.

11/03/2017: I will try to convert it to a WebExtension, but as of now, WebExtensions cannot set preferences, which means there's no standard way to set navigator.* properties. You can vote for the following bug to request this feature for WebExtensions:
Your options will probably be:
1. If i convert to a WebExtension, you could use it with HTTP User-Agent header spoofed, but navigator properties not spoofed.
1.1.Until the bug above is fixed, I will try to provide a user.js file (probably somewhere under
) so that users could spoof navigator properties as well by saving that file under their profile folder (with manual updates required until the bug above is fixed).
Once the bug above is fixed, i would try to release an update also spoofing navigator.* properties.
2. Switch to an ESR release, & continue to use pre-WebExtensions Blend In (but values will get more and more obsolete over time).
3. Not to spoof anything (i.e., not to try to blend in (perhaps until the bug above is fixed)).

Rated 4 out of 5 stars

I believe there's either a bug or incompatibility that doesn't work with my TB 10 (esr). The "thunderfoxing" cannot be undone when toggling the "extensions.tildebirlik.privacy.blend-in.messenger.thunderfoxing" string. Also, I see NO OTHER values in about:config except "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:40.0) Gecko/20100101 Firefox/40.0". So, I assume, it's simply not possible to use an updated (most used) TB user agent (and not FF 40). As ulf3000 below said, this would make TB actually more fingerprintable. But works fine for me in FF.

ADD: In answer to your reply, "As of now restart is required upon change of thunderfoxing setting"
-That's not the issue, I did restart. With the latest "Blend In" versions there simply seems to be no entry in TB's "about:config" for a most used version of TB (only a FF entry). The last "Blend In" version that still had such a TB entry seems to be Blend In 38.0t31.6.0 which I'm sticking to, right now.

This review is for a previous version of the add-on (40.0t38.1.0). 

This is also mentioned in About this Add-on section.

But i'll try to automate this for v41 (or v42).

Follow-up on ADD:
I just tried this using v40.0.3t38.2.0 on Linux, and it works as expected:
1. With thunderfoxing: "Firefox/40.0"; build-id is "20150826023504"; oscpu is "Windows NT 6.1; WOW64", etc.
2. Toggled thunderfoxing to false, quit, &amp;amp;amp; started again: "Thunderbird/38.2.0"; build-id is "20150813074416"; oscpu is "Windows NT 6.1; WOW64", etc.
This stuff is shown under .applied, but better checked by setting Start Page to a URL that shows this stuff.
So i'm unable to reproduce this issue. Perhaps worth trying with a new profile (-ProfileManager)...
Also, will try to set up a place for bug reports (like there is for my IA addon) some time in the near future...
FYI, the just released v43.0t38.4.0 has the following 2 new features which you might find useful:
* Thunderfoxing setting's changes now take effect immediately (re-start is not required).
* Settings can now be viewed on a newly added local page (as opposed to having to view them by accessing a 3rd-party page): resource://blend-in/blended-in.html.

The URL from the 2nd feature, can be set in Tools->Options (Edit->Preferences): Location & accessed conveniently by using

Thank you for your feedback.

Rated 5 out of 5 stars

This is a follow up to my previous review/question...

Thunderbird includes a boolean pref "general.useragent.compatMode.firefox" that can be set to true to automatically insert a Firefox token into the user agent string, like this:

"Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0 Thunderbird/31.5.0 Lightning/3.3.2"

More details here:


This has solved my previous problem with opening Outlook.com from within TB. So even though this is one of the few User Agent Add-ons that actually works with Thunderbird, I won't need it after all.

Again, five stars for functionality for this add-on, which actually has nothing to do with Thunderbird in particular. :@)

This review is for a previous version of the add-on (36.0.1t31.5.0.1-signed).  This user has a previous review of this add-on.

Rated 5 out of 5 stars

Could you include an array of buildIDs keyed to specific FF versions, auto-detect the FF version and use the associated buildID? This would help to reduce potential website compatibility issues that can result if the addon is updated before Firefox itself is updated (or if using Firefox ESR (Extended Support Release)).

This review is for a previous version of the add-on (36.0t31.5.0.1-signed).  This user has a previous review of this add-on.

Since buildIDs are version-specific, &amp; latest agile release is the most common, the current implementation seems adequate for blending in as far as buildIDs go.

Users who'd like to stay at an older release or ESR release AND not blend in their versions with the crowd can disable auto-updates for Blend-in in Shift+Ctrl+A or globally by setting extensions.update.autoUpdateDefault;false in about:config.

Users who need to temporarily unblend in for compatibility or software download reasons, etc. can toggle
in about:config.

P.S. I've tried to keep this project low-key, but could consider registering it on mozdev.org, for instance, for enhancement requests, etc.

Rated 1 out of 5 stars

good intention , but this won´t work , it actually makes you even more fingerprintable!

This review is for a previous version of the add-on (35.0t31.4.0.1-signed). 

Rated 5 out of 5 stars

Super program!
But recently there is a problem with google maps not showing any results and looking locked.
Can someone verify this behavior.

This review is for a previous version of the add-on (30.0t24.6.0.1-signed). 

I haven't had any issues with Google Maps and Blend In. When you are having an issue, try toggling notApplicableIfRealPlatformIsWindows in about:config page; if you are still having an issue after that, then it's not related to Blend In.

P.S. If you can come up with the actual steps to reproduce, feel free to post them; but i'm quite certain it's not a Blendin' issue. :)

Rated 5 out of 5 stars

Does exactly what the description says.
On another note, I also do know that extensions like this one can cause some updating problems (depending on the system you're using) for some downloadable programs (like iTunes, Flash, Java). However, this can be fixed simply by disabling this extension temporarily if a 32-bit program doesn't like your 64-bit system. Overall, this is a good extension as this extension does what it is supposed to do.

If you would like more ideas/etc for your extension. Please locate my e-mail on my profile and I will get back to you as soon as I can.

Very nice developer who keeps this extension up-to-date with browser updates that come along. For example, Firefox 27.01 was updated to Firefox 28 (The developer keeps this extension up-to-date with change). Very well done as this is difficult to do!

This review is for a previous version of the add-on (27.0t24.3.0.1-signed). 

Rated 5 out of 5 stars

This add-on does exactly as the description says. Developer has done a good job keeping up with the fast development cycle. Unfortunate more are not using this add-on as it would become more powerful against fingerprinting with ubiquity. Received my lowest score to date with Panopticlick using this add-on and NoScript.

This review is for a previous version of the add-on (22.0t17.0.7.1-signed). 

Rated 4 out of 5 stars

The version for Firefox 8.0 that has yet to be approved does not work. But the idea is very good. So that's why I rated it a 4 out of 5.

This review is for a previous version of the add-on ( 

Rated 4 out of 5 stars

Works as advertised, simply and cleanly changing the operating system reported by your browser. However, if you're looking for anonymity (not sure why else you would use it), this has pretty minimal effect. This is not the fault of the plugin, it's just that the OS doesn't actually convey all that much identifying info since there aren't all that many to choose from. Things like plugins and font lists are far more informative. Also, changing the OS reported by your browser makes a lot of download pages (including Firefox's) more difficult to use because they'll automatically present you with links to the OS they think you're using.

This review is for a previous version of the add-on (5.0.1-signed).