Q&A Forum > > Reply To: Browser Fingerprint : What is Gekko 20100101 ? Start a new discussion September 23, 2020 at 1:04 pm #45292 TeamKomando:JohnParticipant @264458 Hello Leftblank15, Gecko is a browser engine developed by Mozilla. It is used in the Firefox browser, the Thunderbird email client, and many other projects. You will not be able to update this by itself, updating your Mozilla software should take care of updating the browser engine.