Some Companies That Started as Side Projects

You never know what you may end up with when you start a tiny side project. The followings were some side projects that turn into million-dollar businesses.


Twitter was a small side project created by a podcast company called Odeo during a company hackathon.


Mailchimp launched in 2001 and remained a side project for six years. Now it is generating $600 million in revenue.


Instagram was a spin-up project from Burbn, the location-based app for whiskey lovers when they found people sharing photos instead of locations in the app.


Stewart Butterfield is the master of side projects. Before, it was Flickr while trying to build a game. Now he did it again with Slack that started as their in-house communication tool.


“It all started with a domain, a cheap slice from Slicehost, and some stock art,” said Chris Wanstrath to 37signals.

Khan Academy

Sal Khan started Khan Academy while working as a hedge fund analyst by creating 10-minute Youtube tutorial videos for his cousins.


Craigslist was started by a former IBM Employee Craig Newmark as an email list for local events to help him meet people.


AppSumo was just a landing page and a form to collect emails. Noah Kagan built it as a side project while working for


Gumroad was built in a weekend by Sahil Lavingia while being employed as a designer at Pinterest.


By leasing some space in the building they worked, Neumann and his co-founder hoped that would bring extra cash. That's how WeWork started.


Buffer was started by Joel Gascoigne with a website explaining the idea to get validation. He built it after a few people signing up.