With the amount of content constantly increasing, finding what you are looking for on the web can be overwhelming. It’s only with the help of search engines and other aids that we are actually able to find anything effectively. Here are few such aids to increase your productivity:
Mainstream Search Engines
Google gained a lot of traction initially because of its simplicity and excellent results. It is still the most prevalent search engine out there and is continually improving with products such as image and video searching, searching within its online library of books, scholar searching which provides only results with a scholarly background, as well as many other options. 
Bing is the most common alternative to Google. If you are unable to find something on Google, you may find it with Bing. In addition, if you can’t verbalize what you are looking for, you can perform a Visual Search. The site even allows you to filter your searches. For example, if you are looking for an automobile and all you know is that it’s an SUV, you can filter to show only SUVs. If you know that it was a Chevy, you can filter it even further. These features make it more than just a Google-alternative.
Knowledge Searching
Wikipedia is a great resource for finding information that is well established and of the type that would be in an encyclopedia.
WolframAlpha describes itself as a “computational knowledge engine” or a finding engine, as opposed to a search engine. What sets it apart is that actually returns answers to your search request, as opposed to just a list of pages that might have the answer.
Google Scholar allows you to broadly search for scholarly literature, whether it is papers, theses, published books, or even unpublished books.
Current Events
Twitter Search is a way to search all the Twitter posts (“tweets”).
Combo/Specialized Searching
TinEye is a “reverse image search” which allows you to upload or enter the URL of an image and search for it across the web.
Google Squared is a variation on their search engine which puts the search results into a exportable matrix. While it’s still under development, it’s a great way to put search results into an convenient form.
Dogpile is combo search engine. It returns the top results of the most popular search engines (Google, Yahoo, Bing, & Ask).
Rollyo is a search engine that allows you to search only the websites or types of sites you want to.
Goofram is a combination of Google and WolframAlpha. It allows you to see the search results of both services on one page.
