UnderLine - Live Typing Chat
Ad-Free Messaging with Friends
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
Your words reach the other person as you type. UnderLine is a one-to-one messaging app that shares text in real time before you tap Send, with end-to-end encryption.
UnderLine is a one-to-one messaging app that lets your conversation partner see your words in real time while you type.
Unlike conventional messaging apps, where the other person sees your words only after you tap Send, UnderLine lets the conversation begin from the moment you start typing. When you delete draft text, the change is also reflected on the other person's screen. This makes it possible to share the rhythm of a conversation and the way words take shape, even when you are apart.
Key features
- Real-time display of text while it is being typed
- Simple one-to-one messaging
- Add friends using public IDs or QR codes
- See in your conversation list when someone is typing
- Search your contacts, and your conversation list by name or message
- Mute notifications, pin conversations, or hide them from your list
- Push notifications for new messages
- Blocking, reporting, and in-app account deletion
- Encrypted device-to-device transfer using a QR code
- Encrypted iCloud backup and restoration
Message bodies and live-typing text are end-to-end encrypted. Push notifications never include message content.
Important notes
- Live typing is visible while the other person has the same conversation open. Because text may be seen before you tap Send, do not type anything you do not want the other person to see.
- Enable notifications to receive new-message alerts while the app is in the background or closed. Message content is not shown in notifications.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
UnderLine 2.1 makes live-typing conversations safer and smoother.
• New end-to-end encryption for messages and live typing
• A steadier live-typing row and message field, and better layout at large text sizes
• Search your contacts, and your conversation list by name or message; mute, pin, or hide individual chats
• Reports can now include optional details and images
• Added an open-source licenses screen in Settings
• Fixed issues affecting notifications, sign-in, adding friends, and unblocking
Please note
Chat history from earlier versions can be viewed only for messages this device has already displayed (not on a new device). Chat-history backup/restore and device-to-device transfer are not provided.
The developer, 5mm, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
- Contact Info
- User Content
- Identifiers
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- 5mm
- Size
- 67.2 MB
- Category
- Social Networking
- Compatibility
Requires iOS 15.6 or later.
- iPhone
Requires iOS 15.6 or later. - iPod touch
Requires iOS 15.6 or later. - Mac
Requires macOS 12.5 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- Japanese
- Age Rating
16+
- 16+
- Infrequent
Cartoon or Fantasy Violence
Realistic Violence
Profanity or Crude Humor
Mature or Suggestive Themes
Horror/Fear Themes
Alcohol, Tobacco, Drug Use or References
Sexual Content or Nudity
Guns or Other Weapons
Contains
Messaging and Chat
User-Generated Content
- Copyright
- © 2026 5mm.fun