An Instagram DM can be about 1,000 characters long. Instagram doesn't publish an official limit for messages typed in the app, but its messaging API, which every DM automation tool uses, accepts text of up to 1,000 bytes per message.
| Limit | Value |
|---|---|
| Text per message (API) | 1,000 bytes |
| Quick-reply buttons per message | 13 |
| Characters per quick-reply button | 20 |
| Private replies to a comment | 1 message, within 7 days of the comment |
| Messaging window after someone writes | 24 hours |
| Window for a human agent | 7 days |
| Note length | 60 characters |
Bytes, not letters
The API counts bytes in UTF-8, and not every character is one byte. That matters if you write in another alphabet or use emoji:
| Characters | Bytes each | About how many fit in 1,000 bytes |
|---|---|---|
| English letters, digits, spaces | 1 | 1000 |
| Accented Latin letters (é, ñ, ş), Cyrillic, Arabic, Hebrew | 2 | 500 |
| Chinese, Japanese, Korean | 3 | 333 |
| Most emoji | 4 or more | 250 |
So a Russian or Arabic message sent by an automation tool fits about 500 letters, and a Japanese one about 330. Keep automated messages well under the limit, or split long text into two messages.
Buttons and quick replies
A message can carry up to 13 quick-reply buttons, and each button label shows up to 20 characters before it's cut off. Short labels such as "Send me the link" work best.
Replying to comments by DM
A business can send one private reply to a comment, within 7 days of the comment. It can only send more if the person replies, and then within 24 hours of their reply. That's why comment-to-DM automations open with one short message and a button. See how comment-to-DM automation works.
The 24-hour window
After someone messages a business, the business can reply freely for 24 hours, and each new message from them restarts the clock. When a person on your team needs longer, Instagram allows a reply tagged as a human agent for up to 7 days. MuChat follows these windows automatically: see Instagram's messaging rules.
Turn comments into conversations
MuChat answers Instagram comments, story replies and DMs automatically. The Free plan needs no card.