Series iResearch (06): The 20 Best OSINT Add-Ons for Mozilla Firefox


Firefox as OSINT Browser

About 80 percent of the work on Internet research or Open Source Intelligence (OSINT) is done in the browser. One more reason to know the browser exactly and to use it optimally. But only with the selection of the right add-ons does Firefox become the perfect OSINT browser.

With the release of Firefox Quantum and the conversion of the add-ons to web extensions (since Firefox version 57), a lot has happened with the add-ons.

Add-ons are supposed to support and help, but which ones are the right ones? These and other questions about the Firefox add-ons are answered in this post. I have listed my personal TOP 20 of the best browser add-ons, sorted by categories.


Add-on FAQs

During our workshops, certain questions in connection with add-ons arise again and again. Here are some FAQs on the topic:

What Are Add-Ons for Firefox?

Add-ons are useful helpers for the workflow. You add new functions to the browser or adjust the functions. This improves productivity and also increases security.

Which Add-Ons Can I Install?

It is always important to pay close attention to which add-ons you want to install and from which source they originate. Ask questions such as: Where does the add-on have access to and to which destination does it send my data? You should also check user feedback and the number of installations. Equally important is compatibility with the current browser version.

See also who the developer is and check his rating. Check whether the version offered is current. You should not install outdated versions.

How Do I Install Add-Ons in Firefox?

Click the menu button and select add-ons. The add-ons management opens. Select the “Discover add-ons” section in the add-ons management tab. If you want to install one of the presented extensions, click on the “grey toggle button”, which turns green. To remove the currently installed extension, click on the “Toggle button” again.

Excerpt from the Mozilla Help

Is There an Add-On Manager for Firefox?

Unfortunately not. It would be nice if there would be a version for Firefox from Extensity, but due to the system (restrictions by the new API) no such add-ons are offered.

The maintenance of the browser is nevertheless very important. Installing add-ons not only adds functionality to Firefox, but also expands it. The more add-ons you install, the more likely Firefox will start slower and no longer run optimally. Then it helps to delete or deactivate rarely used add-ons.

How Can I Delete or Deactivate Firefox Add-Ons?

You can disable add-ons without removing them:

Click on the “Menu button” and select Add-ons. The add-ons management opens.

Select the section “Extensions or Themes” in the tab with the add-ons management.

Select the add-on you want to disable.

Click on the “Deactivate” button.

Click on “Restart now”. Your open tabs are saved and restored after you restart Firefox.

Excerpt from the Mozilla Help

How Do Firefox Add-Ons Stay Up to Date?

Click on the “Menu button” and select Add-ons. The add-ons management opens.

Select the “Extensions” section in the add-ons management tab.

Click on the gear symbol at the top right.

Select: Switch all add-ons to automatic update.

Excerpt from the Mozilla Help

One more word about the handling of tools and add-ons. Start with a few selected add-ons. Select only those that support your goals in a meaningful way. Delete non-functioning tools. You can also split add-ons across different browser profiles to customize the browser environment according to the focus of your work.

The TOP 20 OSINT Add-ons for Firefox

Now we come to my personal selection of the TOP 20 add-ons for the Firefox browser.

Privacy & Security & VPN

The add-on protects the browser immediately after installation at a good level against intrusive advertising, tracking and other harmful content.

If you want a higher level of protection, click the uBlock Origin icon and select the Dashboard icon:

uBlock Dashboard

Via the tab “Filter” you can then add further filter lists to your configuration, e.g. annoyances or further spyware filters. After the selection please click the “Update button” and update all filters.

You will reach websites which block the display of content because of the adblocker. Then call up the menu again by clicking on the “Icon”. Click on the “big blue icon” to turn off the blocker for this website.

FoxyProxy is a Firefox extension that automatically connects to the Internet via one or more proxy servers based on URL patterns.

The proxy server is switched on the basis of the URL you defined and the switching rules. So you can use certain urls with a suitable VPN.

The setup requires some effort, but then the tool works as it should.

Many websites offer only limited support for encryption via HTTPS.

The HTTPS Everywhere enhancement resolves these problems by rewriting all requests to these requests to HTTPS.

User-Agent Switcher can quickly and easily change the user agent of your browser. There are currently 26 user agent strings to choose from.

The selection is quite self-explanatory. It goes from mobile devices, via desktop browsers to operating systems.

With the add-on you can also use Firefox on older pages, which expect e.g. Internet Explorer as browser. You can also bypass scripts from websites that require e.g. Mac OS as operating system and otherwise display nothing.


Select a text area on a Web page and right-click to open the context menu. Here you will find two options for Google Translate:

a) Translate selection (max. 1100 characters)
b) Translate the whole page

I prefer the translation of the selection. This is done directly on the website in the browser. This is especially useful for pages that Google can’t access because the content is behind a login (e.g. Facebook, forums and the like).

Image Information - Image Search

Displays the Exif, IPTC-NAA/IIM and IPTC core metadata as stored by digital cameras. This works with local and web-based JPEG images.

Right-click on an image to select the “Exif Viewer”. A separate window opens with the available information about the image.

This Firefox extension adds a number of customizable options to the right-click menu of images. These options allow fast and efficient use of many reverse image search engines.

You can add your own websites, customize existing ones, and search multiple websites at once.

In the Firefox add-on directory (about:addons) you can set some important options:

The desired search engine can be selected individually by right-clicking on it. Alternatively, you can query all search engines.

History & Cache

With this extension you can search for archived or cached versions for each web page.

The following services are used for this:

  • Google cache
  • Google Cache (text only)
  • The Wayback Machine (Internet Archive)
  • WebCite
  • Memento Timetravel


Monitor web pages or feeds for changes. The add-on has an alert function and other (premium) functions.

My favorite RSS reader! I use it mobile and via the extension in my web browser.

Inoreader helps you keep track of your key information sources, monitor keywords or social feeds, store pages for later viewing and access all your articles at any time with a powerful free search and a complete subscription archive.

Text & Screenshots

Capture the entire web page or a desired section of it. Capture the entire browser window including scrolling function.

You start the tool via:

  • The icon in the menu bar
  • Right-click on the website
  • A self-defined hotkey.

Additional premium features (including OCR) are available as subscriptions.

Do what it promises; copy text from the web page to the cache without any formatting.

First, set the value for “devtools.jsonview.enabled” to “false” in “about:config”.

With the extension JSON and XML files can be viewed in the browser and do not have to be saved beforehand.

Scraping & Downloads

Video DownloadHelper is the most comprehensive tool for extracting videos and image files from websites and saving them to your hard drive.

The tool is shown with an icon (three grey dots) in the menu bar. If the accessed web page contains media content (such as videos), the icon becomes colored.

With a click on the icon you can now select the desired format for the download.

I recommend the following settings via the “Settings”.

Behavior tab:

  • Set the “Default download directory” to the desired directory.
  • “Set “Max concurrent downloads” to 20
  • “Max Variants” = 99
  • “Enable “Hide ADP Versions

With the add-on you can easily download large amounts of media files. On the target page, start the tool via the icon in the menu bar.

A new window will open in which you can set various filters, such as only video files for downloading.

You may need to reload the target page to see the entries in the filter window.

IP & Domain

The tool provides detailed information about each IP address, domains, and provider.

Of course, the add-on does not replace a detailed search, but it is always good for a quick check.


If you have too many tabs open, click the OneTab icon to convert all your tabs to a list. If you need to access the tabs again, you can restore them individually or all at once.

You can also pass all tabs as a “group” or export/import them. 

I use the export whenever I have opened a large number of URL’s in tabs and want to edit them with other software, for example.

LastPass is a recommended password manager. The add-on simply works well and is very useful. Of course, there are also voices that speak against the use of a password manager. Especially one that stores the data in the cloud. See for yourself. 



Multi-Account Containers help you to keep different activities – such as investigations in social networks, online marketplaces, shopping, or checking work e-mails – separate.

The extension separates the memory area of the web pages into tab-specific containers. Cookies from one container are not available for another container.

For example, you can log in to two different container tabs with two different accounts on a website.

You can also assign selected social networks to a specific container tab. For example, for various alias identities that you need for investigations and searches.

After installing the Firefox Multi-Account Containers extension, click the Container icon to edit your containers. Then you can change the colors, names, and symbols individually.

For more information, I recommend these posts:

Optional Add-ons:

Since the conversion from Firefox to the new WebExtensions a lot has happened in the plugin landscape. Some of the formerly very good plugins were not maintained further, others are not yet completely adapted.

The following list contains plugins that

are not (yet) compatible,
can be used as an alternative for the above plugins,
can be used as a supplement.





Choosing the right add-ons to turn Firefox into an OSINT and research browser is not a one-time thing. Instead, you must regularly check the installed add-ons and deactivate them if necessary. Keep track of possible new tools and try them out. But with the selection of my TOP 20 add-ons for Firefox described in this post you have a good basis for the start.

In the next post in this series, I’ll explain how to set up Chrome as an investigative browser.

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