How do I delete characters, words, and lines without leaving insert mode?

Explanation

Vim provides three levels of deletion directly in insert mode, so you don't need to switch to normal mode for small corrections.

The three levels

How they work

<C-w> deletes backward to the start of the previous word:

Before: The quick brown fox█
<C-w>:  The quick brown █
<C-w>:  The quick █

<C-u> deletes everything you typed on the current line since entering insert mode:

Before: function processData(input) {█
<C-u>:  █

Why this matters

These three keystrokes eliminate the most common reason to leave insert mode — fixing a typo:

• Mistyped a character? <C-h> (don't reach for Backspace)
• Mistyped a word? <C-w> (don't escape, daw, i)
• Wrong entire line? <C-u> (don't escape, dd, O)

Tips

• <C-w> and <C-u> also work in the command line (: prompt) and search (/ prompt)
• These are actually terminal shortcuts, not Vim-specific — they work in bash, zsh, and most Unix programs
• <C-w> respects the iskeyword option for word boundaries
• <C-u> only deletes text entered during the current insert session, not text that was already there
• These keystrokes are significantly faster than switching to normal mode for small edits