SearchEngineSwitcher от Jordan Schroder

When you're using one of the supported search engines, this extension embeds helpful links to other alternative search engines, with your latest search criteria, along-side the search bar!
Currently, we support four search engines: Google, DuckDuckGo, Ecosia, and Bing.

If you aren't interested in using certain search engines, you can disable them in the extension's pop-up.