Follow the instructions on adding a search engine to Firefox by Mozilla.
Just by visiting the site, Chrome should have already stored it as a search engine. Just go to Chrome's search engine settings and find duckduckstart.com in that list, then click "Make Default" next to it.
DuckDuckStart should be easy to add to any browser or launcher (Alfred, GnomeDo, etc.) that supports custom searches.
Just use this search string in your browser/launcher's search engine options to create a custom search:
(Replace SEARCH with whatever your browser/launcher expects the placeholder to be).
Please note: DuckDuckStart accepts both POST and GET requests. However, POST is strongly preferred, as it prevents leaking of search queries that are sent to StartPage.
If you would like to use another search engine other than Startpage (Like Bing or Yahoo), simply put the url and a
%q where the search goes, like so:
For example, if you use Chrome and want to default your search to Yahoo, use this:
Make sure to put the
http:// or the
https:// before the URL.
Also be aware that DuckDuckStart will default to startpage.com if there is an error in the syntax.