According to Microsoft, the size limit for a message in chat is “Approximately 28 KB per post…an approximate limit because it includes the message itself (text, image links, etc.), @-mentions, and reactions“. What? How many words is 28 KB?

I wanted to look at this because a colleague had created an average length message, but was stopped from sending the message by the pop up: “You’ll need to shorten your message to send it”. They were convinced the message wasn’t that long.

For convenience, I opened Word and used =Rand() to create random text, then cut and pasted it into a Teams chat message. I hit the above limit at around three pages or 1460 words or 7,870 characters (including spaces).

This was less than expected and was down to a hidden gotcha: there is formatting behind the text eating my character limit in the chat. Could this be the problem my colleague was running in to? Maybe.

I tried clicking the Clear all formatting button:

This allowed me to increase the character to the Word equivalent of six pages or 2721 words or 14,600 characters (approx.). I was losing around half of the available character count to hidden formatting! Copying and pasting the text into, and out of notepad had the same effect.

So, if you hit the above limit sooner than you expect, try clearing your formatting if you have cut and pasted from another application.

Have you run into this? My testing was quick and dirty, please share in the comments below if you can add anything to this topic.