A lock icon appears to the left of address bar in web browsers most of the time. It indicates that the network connection is a secure channel between the browser and site. Basically, a https connection. But it does not indicate website trustworthiness. Even phishing sites use HTTPS. So, Google is replacing the lock icon in Chrome with a variant of the tune icon that acts as an entry point to site controls. Google settled with variant of tune icon because of following reasons:
- Does not imply “trustworthy”
Is more obviously clickable
Is commonly associated with settings or other controls
When you click the new icon, you will get controls and additional security information about the website you visited.
The new icon is scheduled to launch in Chrome 117 on desktop, which will be released in early September 2023. If you are running Chrome Canary, you can enable Chrome Refresh 2023 at chrome://flags#chrome-refresh-2023. Google will do the same on Android as well. On iOS, Google will remove the icon itself.