How do I tell if my connection to a website is secure?

No one has helped translate this article yet. If you already know how localizing for SUMO works, start translating now. If you want to learn how to translate articles for SUMO, please start here.
Please update your version of Firefox for the latest features and security updates.

The Site Identity button (a padlock) appears in your address bar when you visit a secure website. You can quickly find out if the connection to the website you are viewing is encrypted, and in some cases who owns the website. This should help you avoid malicious websites that are trying to obtain your personal information.

site identity

The Site Identity button is in the address bar to the left of the web address. Most commonly, when viewing a secure website, the Site Identity button will be a green padlock.

green lock 42

However, in some rarer circumstances, it may also be a gray padlock with a yellow warning triangle or a broken padlock (a padlock with a red strikethrough).

blocked secure 42 orange triangle grey lock 42 unblocked mixed content 42

Note: Clicking the Site Info button button at the left of the address bar brings up the Control Center, which allows you to view more detailed information about the connection's security status and to change some security and privacy settings.

Warning: You should never send any sort of sensitive information (bank information, credit card data, Social Security Numbers, etc.) to a website without the padlock icon in the address bar - in this case it is neither verified that you are communicating with the intended website, nor is your data safe against eavesdropping!

Green padlock

A green padlock (with or without an organization name) indicates that:

  • You are definitely connected to the website whose address is shown in the address bar; the connection has not been intercepted.
  • The connection between Firefox and the website is encrypted to prevent eavesdropping.

green lock address bar 42

A green padlock plus the name of the company or organization, also in green, means this website is using an Extended Validation (EV) certificate. An EV certificate is a special type of site certificate that requires a significantly more rigorous identity verification process than other types of certificates.

site identity site identity fx39 Linux en

For sites using EV certificates, the Site Identity button displays both a green padlock and the legal company or organization name and location of the owner of the website, so you know who is operating it. For example, it shows that mozilla.org is owned by the Mozilla Foundation.

Gray padlock with yellow warning triangle

A gray padlock with a yellow warning triangle indicates that the connection between Firefox and the website is only partially encrypted and doesn't prevent eavesdropping. This also appears on websites with self-signed certificates or certificates that are not issued by a trusted authority.

grey lock yellow tri url bar 42

For information about what "partially encrypted" means, see Mixed content blocking in Firefox. This is a problem the site developer needs to resolve.

Note: Do not send any sort of sensitive information (bank information, credit card data, Social Security Numbers, etc.) to sites where the Site Identity button has a yellow warning triangle icon.

Gray padlock with red strikethrough

A padlock with red strikethrough indicates that the connection between Firefox and the website is only partially encrypted and doesn’t prevent against eavesdropping or man-in-the-middle attacks.

lock red strikethrough 42

This icon will not appear unless you’ve manually deactivated mixed content blocking.

Note: Do not send any sort of sensitive information (bank information, credit card data, Social Security Numbers, etc.) to sites where the Site Identity button has a gray padlock with red strikethrough icon.

Was this article helpful? Please wait...

These fine people helped write this article: AliceWyman, Chris_Ilias, philipp, underpass, novica, Tonnes, michro, Verdi, gerv, scoobidiver, John99, foxytechguy, Joergen, cammy_the_block, tanvi, upwinxp, grubert, scootergrisen, jsavage, Artist, Parmswagga, eliemichel, dmitriev. You can help too - find out how.