Multiline input lets you compose long prompts without hitting submit on every line break.

What it does

Shift+Enter, Option+Enter, or a trailing backslash followed by Enter all insert a newline into the prompt buffer instead of sending it. You can paste multi-line code blocks, write step-by-step instructions, or draft a structured prompt in place. Regular Enter still submits when you're ready.

When to use it

Pasting code samples, logs, or error messages into a prompt.
Writing a structured brief with sections and bullets.
Composing a prompt that mixes prose with file paths or commands.
Any time your prompt is longer than one terminal line.

Gotchas

Some terminals don't distinguish Shift+Enter from Enter. Use backslash + Enter as a universal fallback.
Bracketed paste mode affects how multi-line pastes are interpreted - enable it in your terminal config.
Vim mode has its own multiline behavior. Use o from normal mode to open a new line cleanly.

Official docs: https://code.claude.com/docs/en/interactive-mode.md#multiline-input