Required field indicator.
Marks a value that must be provided to complete a form.
See it in context
What it is
Required status may be expressed with text or a symbol explained once for the form. The requirement should also exist in the control’s semantics, not only its visual label.
When to use it
Explain required markers and communicate the requirement programmatically.
Know the difference
Optional is a field rule; disabled means the control cannot currently be changed.
Across platforms
Web
Use a native button for an action and an anchor for navigation. Preserve keyboard activation and a visible focus indicator.
iOS · iPadOS · Android
Provide a comfortable touch target, use familiar system symbols when appropriate, and show a clear pressed or selected state.
macOS · Windows · Linux
Keep pointer, keyboard, and focus behavior consistent. Common commands can additionally expose a menu item or keyboard shortcut.
Go to the source
Primary documentation for the pattern and its platform conventions.