Instagram does not notify users when you screenshot a regular direct message (DM) conversation, including text, shared posts, photos, and videos that are not set to disappear. You can freely take screenshots of these regular DMs without the sender receiving any notification. However, Instagram does notify users if you screenshot disappearing messages, photos, or videos sent in a DM. This includes content sent in Vanish Mode or messages/photos/videos sent with the "View Once" or "Allow Replay" options. In these cases, the sender receives a notification that their disappearing message has been screenshotted. In summary:

• Screenshotting regular DMs: No notification sent.
• Screenshotting disappearing or vanishing DMs (messages, photos, videos): Notification is sent to the sender.

This is the current policy as of 2025 on Instagram screenshot notifications for DMs.