100DaysOfCode

Twitter 2016-07 education active Updated 2026-02-21
Late 2010s Major 120 million+ lifetime posts

First documented in July 2016 on Twitter. Currently active and in regular use across social platforms since 2016.

Also known as: 100DaysChallengeLearnToCodeCodeNewbie

The coding challenge that convinced thousands of aspiring developers to code for at least one hour daily for 100 days.

Public Commitment

Alexander Kallaway started #100DaysOfCode in July 2016 as personal challenge: code minimum one hour daily for 100 days, tweet progress daily with the hashtag. The public accountability worked—others joined. The challenge spread across Twitter, creating supportive community of beginners and career-switchers learning to code.

FreeCodeCamp Connection

FreeCodeCamp promoted #100DaysOfCode heavily. The challenge paired perfectly with free coding education—structured timeline, daily practice, community support. Thousands participated, sharing GitHub commits, project progress, and struggles. The visibility attracted recruiters—some participants landed jobs mid-challenge by building public portfolios.

Sustainability Questions

Completion rates were low—many quit by Day 30. The rigid structure (every single day) was unsustainable for people with jobs, families, or burnout. But even incomplete attempts often resulted in learning. By 2023, #100DaysOfCode had millions of posts and countless success stories, proving public challenges could motivate self-directed learning.

References:

Explore #100DaysOfCode

Related Hashtags

2010 2016 #100DaysOfCode 2016 #99PercentInvis… 2010 #99PI 2010 #LearnToCode 2011 #AcademicTwitte… 2011 #3Blue1BrownMath 2015 #3Blue1Brown 2015
Related hashtags by year of first appearance — circle size reflects lifetime volume, fade reflects how active each tag still is.