A young woman giving two thumbs up with an annoyed expression on her face.

Has someone sent you the letters “IK” in response to your informative message? It’s the easiest way to convey that you’re not out of the loop. Here’s what this acronym means and how to use it in your next text conversation.

I Know

IK means “I know.” It’s used in text messages and social media to convey that you already know about something. For example, someone might say to you, “The weather’s going to be rainy tomorrow. Bring an umbrella.” If you already read the weather report, you might reply with “IK.”

You can also use it to respond to someone asking if you knew about a particular fact. For instance, someone messages you, “dId you know that our favorite coming band is playing a show here next month?” If the answer is yes, you might reply with “IK” instead.

During the early days of the internet, people primarily wrote IK in uppercase. However, with the adoption of mobile phone keyboards as the most common way of typing out messages, it’s widespread to see IK written in the lowercase “ik” or even the sentence-case “Ik.” Be careful — it’s easy to get the uppercase “I” confused for a lowercase “L.”


Nowadays, young people mostly use IK in text messages. Like a few other acronyms, you can use it in a message entirely on its own since it forms a complete sentence. You can deploy it in various contexts, from discussing household errands to talking about the latest breaking news.

The Origin of IK

IK is a very early internet acronym, popping up around the same time as its counterpart IDK. It’s part of a group of internet acronyms that started in online chats and messages to type messages faster and fit them within character limits. The first definition for IK on the internet slang repository Urban Dictionary was created in October 2004 and reads, “Used in IM. Means I Know.” In this definition, “IM” means “instant messenger.”

Eventually, IK spread across the internet, with people of all ages using it in direct messages. But, while you might occasionally find it on social media platforms like Twitter and Facebook, it’s particularly popular in private conversations between people.

IK is essentially the exact opposite of the acronym “IDK,” which means “I don’t know.” IDK helps convey your confusion or ignorance about something, while IK clarifies that you already knew about it.

Of Course, I Know

As with every internet acronym, using IK has some critical differences to its non-acronym version, “I know.” While the latter is a simple way to highlight your pre-existing knowledge, the former can take on an “annoyed” tone. It might even suggest that you’re insulted at their assumption of ignorance, and you feel that they’re “talking down” at you.

For example, if someone tells you, “don’t forget to unplug all the appliances before you leave the apartment,” when that’s something you always do, you might reply with “ik.” The short, blunt nature of the acronym on its own gives it a dismissive tone, similar to other slang terms like NVM or the simple “K.”

However, as with anything people say on the internet, it can be difficult to read tone and intention into a bunch of text. Before you get up in arms about someone messaging you with “ik,” make sure to figure out what they mean first. Some acronyms do just that, such as WDYM.


IK can also imply that a message is basic knowledge or common sense. For example, if someone says to you, “You should try not to burn yourself,” you might reply “IK” because everyone already knows they should avoid getting burnt.

How to Use IK

Using IK in your messages is pretty straightforward. When somebody tells you something you already know, reply with “IK.” You can use it in both uppercase or lowercase, however, the lowercase version is significantly more common among younger people.

Here are a few examples of IK in action:

  • “ik”
  • “IK, you don’t have to tell me twice.”
  • “I heard it yesterday, so ik.”
  • “Yes, ik.”

If you want to learn more about the most common internet acronyms, check out our explainers on NP, LOL, and NM. You’ll be a digital slang expert in no time!

RELATED: What Does "NM" Mean, and How Do You Use It?

Profile Photo for Vann Vicente Vann Vicente
Vann Vicente has been a technology writer for four years, with a focus on explainers geared towards average consumers. He also works as a digital marketer for a regional e-commerce website. He's invested in internet culture, social media, and how people interact with the web.
Read Full Bio »