A responsive logo is the term given to a primary logo that exists in several, slightly different and easily scalable variations. The need for flexible/ responsive logo design has grown with the demands of a digital environment. Along with a full brand name used for print, a logo also requires a simplified, short-form version. Often a minimal responsive logo is the first letter of the brand name or its mark/symbol in isolation. A successful responsive logo must still be recognisable even at the top of your browser - as a tiny 16 x 16 pixel favicon.
Unpacking the definition
Easily scalable variations
A responsive logo takes the elements of the main logo and adapts them for different sizes. As much as anything its to ensure the text is always legible. Take the example below, when the main Heineken logo is reduced to the size of a favicon, none of the text is readable.
The demands of a digital environment
Scalable logos come into their own on the web. A website has seconds to communicate its main message – 15 seconds in fact – so arguably you want to use that time to communicate what your business does, rather than what your logo looks like. A logo that takes up less space can then only be a good thing, leaving more space for the main message!
The mark/ symbol within a responsive logo
A mark needs to have the same brand feel as the logo as a whole. If the logo already has an mark of its own (think Airbnb, Nike, Chanel) then working out what the logo looks like scaled down will be fairly easy. If you have a type based logo, then retaining the brand feel whilst reducing the logo size maybe a tricker ask.