How do I reindent a block of code using a visual selection?

Explanation

After making a visual selection, pressing = applies Vim's auto-indent to every selected line at once. This is the most precise way to fix indentation for a specific region without touching the rest of the file — no need to select the whole buffer or manually adjust each line.

How it works

• = is the indent operator in normal mode; in visual mode it becomes an immediate action on the selection
• Vim uses the indentexpr (language-aware) or cindent/autoindent rules depending on your filetype settings
• The selection can be character-wise (v), line-wise (V), or block-wise (<C-v>) — in practice V (linewise) is most useful here
• The cursor returns to the first line of the selection after the operation

Example

Starting with badly indented Python:

def greet(name):
print(f"Hello, {name}")
        return None

Select all three lines with Vjj, then press =:

def greet(name):
    print(f"Hello, {name}")
    return None

Tips

• Use =ip (no visual needed) to reindent the current paragraph — the = operator accepts any motion
• == reindents just the current line
• gg=G reindents the entire file (equivalent to selecting all and pressing =)
• If the result looks wrong, Vim may be using the wrong filetype — run :set filetype=python (or your language) to correct it