You might be browsing the news feed of any social media platform and come across a post that starts with TIL. If you don’t know about its meaning, you may be wondering what does this acronym refer to. There is no need to feel embarrassed as online language abbreviations are numerous and the number is only growing. Don’t worry as we tell you what does TIL mean and how did it originate.
What Does TIL Mean?
The online abbreviation TIL means “today I learned.” It’s commonly used to share something you just discovered and want to pass along. For example, when you learn a quirky historical fact or a nifty kitchen trick, you can lead with “TIL” and then state the fact.
That “new” info can be profound or delightfully trivial—both are fair game. TIL is widely used on platforms like Reddit, X/Twitter, Instagram, and in messaging apps.
Quick note on casing: You’ll see both TIL (uppercase) and til (lowercase) around the web. On Reddit—especially in the r/TodayILearned community—titles traditionally start with uppercase “TIL.” Elsewhere, either casing is understood.
Where and How to Use TIL
On most platforms, put TIL at the very beginning of your sentence or post, followed by a colon or dash. This sets the expectation that you’re about to share a bite-sized fact.
TIL: octopuses have three hearts.
TIL — the Eiffel Tower was once yellow.
If you’re posting to r/TodayILearned, follow the community’s long-standing conventions: make the title a specific, self-contained fact and include a reliable source as the post’s link (not just in the comments). Their wiki explains the norms like “TIL that” vs “TIL about,” avoiding personal anecdotes/opinions, and keeping politics/volatile topics out of scope. See the TIL posting guidelines and the rules & FAQ for details.
The History of TIL
Unlike many chatroom acronyms from the 1990s, TIL caught on more recently. It emerged in the mid-to-late 2000s and surged in popularity with Reddit’s r/TodayILearned community, created in 2008. Today it’s one of Reddit’s largest fact-sharing hubs, with tens of millions of members regularly posting concise, sourced nuggets of knowledge.
Beyond Reddit, the format crossed into mainstream social feeds and even educational media. For instance, National Geographic has produced “Today I Learned” video playlists that package surprising facts into short, shareable clips.
Wrapping Up
In this blog, we discussed what does TIL mean. We also covered the best situations to use it and where it came from. Use TIL to lead a short, interesting fact; keep it specific and source-backed on communities like r/TodayILearned; and don’t worry too much about casing outside Reddit—readers will get it either way.
If you’re interested in online slang, take a look at what does gtg mean in text messaging.
What’s New in This Update
Clarified casing: TIL (uppercase) is customary on Reddit titles; lowercase til also appears on other platforms.
Added practical etiquette for r/TodayILearned (specific fact, source link, no personal anecdotes/opinions) with links to the community rules.
Updated history section to reflect current scale and ongoing usage across social media and educational publishers (e.g., National Geographic’s “Today I Learned” videos).
Tamal is a freelance writer at AddictiveTips. After gaining substantial experience in technology, finance, and business processes in his previous job in an IT consulting company, he adopted writing as a full-time profession 3 years ago. While not writing about the latest technology, he loves to play COD and binge-watch
