The indexed web contains an incredible 14 billion pages. But only a tiny fraction help you improve your brain power. Here are 40 of the best.

whizzpast.com – Learn about our awe inspiring past all in one wonderful place.

khanacademy.org – Watch thousands of micro-lectures on topics ranging from history and medicine to chemistry and computer science.

freerice.com – Help end world hunger by correctly answering multiple-choice quizzes on a wide variety of subjects.

artofmanliness.com – Blog/site dedicated to all things manly, great for learning life skills and good insights.

unplugthetv.com – Randomly selects an educational video for you to watch.

coursera.org – An educational site that works with universities to get their courses on the Internet, free for you to use.

mentalfloss.com – Interesting articles guaranteed to make you smile and get you thinking.

feelgoodwardrobe.com – Find out how the world of fashion really works and what you can do to combat it.

ted.com – Collection of TED (Technology, Entertainment and Design) talks in which knowledgeable speakers address a variety of topics in short videos (< 18 minutes)

lifehacker.com – Learn to hack life! Tips and tricks for improving all areas of your life.

lifehackninja.com – Recently started life hack site that offers lists of useful knowledge

good.is/infographics – A collection of infographics which showcase useful information in an easy to digest visual format.

mathrun.net – Practice your basic maths skills with a simple game.

lizardpoint.com – A collection of browser-based games and the like to improve knowledge of geography, math, and such.

litro.co.uk – All you need to know about the wonderful world of books and writing.

zenhabits.net – Blog about improving your life by making it simpler.

justinguitar.com – Hundreds of free guitar lessons as well as some basic music theory.

duolingo.com – Learn a new language for free while helping to translate the web.

memrise.com – Learn things quickly and efficiently with flashcards that are spaced based on the spacing effect

cookingforengineers.com – A site containing one man’s explorations in food, with step by step instructions for making a wide variety of dishes.

thedatingspecialist.com – A weekly blog run by a professional dating coach offers advice on a wide variety of relationship topics.

nerdfitness.com – Fitness resource for the average person.

openculture.com – Compendium of free learning resources, including courses, textbooks, and videos/films.

charitynavigator.org – Site dedicated to reviewing charities so you can easily research any you’re interested in.

lettersofnote.com – Their tagline says it all: “Correspondence deserving of a wider audience”

thedailymiscellany.com – A daily dose of useful knowledge, quotes, and other random things.

MIT Open Courseware – Free access to quite a few MIT courses that are on par with what you’d expect from MIT.

codecademy.com – Website packed with introductory courses for various programming languages and web technologies.

investopedia.com – Learn about the world of finance, from basic terminology to in-depth analysis of various areas of investing.

udacity.com – Free courses mainly focused around mathematics and programming. Aimed at people of all skill levels.

lang-8.com – Write posts in a language you’re trying to learn, get them critiqued by a native speaker (and in turn help that native speaker learn your language)!

careerbuilder.com – Job hunting site to help you find a new career.

ureddit.com – Reddit’s very own University. Learn from Redditors, or try to teach them.

engineerguy.com – Collection of videos in which Bill breaks down various feats of engineering in layman’s terms.

zooniverse.org – Take part in a huge variety of interesting studies of nature, science, and culture.

quora.com – Ask questions you’re curious about, answer those you’re knowledgeable about. Tailor your own feed to fit what interests you.

thenewboston.org – A fascinating collection of videos and tutorials related to maths and computer science.

aldaily.com – Aggregation of articles from various higher education journals and publications.

noexcuselist.com/everything – A huge list of awesome sites to learn from.

These are our favourite clever websites, but what about yours? If you know any that max power your mind or boost your brain, let us know in the comments below.

livemocha.com – Community dedicated to the idea of everyone being fluent in multiple languages, teach or be taught another language with the goal of conversational fluency.

Want more of the best useful websites? 16 incredibly useful websites that could change your life in 2016