The fastest way: use the Format menu

Open your document in Microsoft Word and select the text you want to change. Highlight it by clicking and dragging, or triple-click a paragraph to select the whole thing. Then go to the Home tab at the top, find the Aa button (it looks like a capital and lowercase letter), click the small arrow next to it, and choose lowercase from the menu that appears.

That's the method that works in Word 2016, 2019, 2021, and Microsoft 365. The button location is the same across all these versions. If you're using an older version of Word, the path is slightly different — go to Format in the menu bar, then Text, then Change Case — but the options are identical.

The change happens instantly. Word doesn't ask you to confirm; it just converts whatever you selected. If you change your mind, press Ctrl+Z (or Cmd+Z on Mac) to undo.

Key Takeaways

  • Select the text you want to change by clicking and dragging or triple-clicking a paragraph.
  • Click the Aa button on the Home tab, then choose lowercase from the dropdown menu.
  • The change applies instantly to your selection only — the rest of your document stays the same.
  • You can undo the change at any time by pressing Ctrl+Z (or Cmd+Z on Mac).
  • Word also offers options for UPPERCASE, Title Case, and Sentence case from the same menu if you need those instead.

What happens if you select nothing

If you click the Aa button without selecting any text, Word will either do nothing or show you a message saying "No text is selected." This is a safety feature — Word won't convert your entire document by accident. You have to deliberately highlight the text first.

If you want to change a whole document, use Ctrl+A (or Cmd+A on Mac) to select all text, then apply the lowercase format. Be careful with this approach if your document has headings or proper nouns you want to keep capitalized — the conversion will affect everything.

Using Find and Replace for more control

If you need to change only certain words or phrases to lowercase while leaving the rest of your document alone, the Find and Replace tool gives you more precision. Press Ctrl+H (or Cmd+H on Mac) to open Find and Replace. Type the text you want to find in the Find what field.

In the Replace with field, type the same text in lowercase. Then click Replace All to change every instance at once, or click Replace one at a time if you want to check each one first. This method is slower than selecting and using the Aa button, but it's useful when you only want to fix specific words — like changing "IMPORTANT" to "important" throughout a document without touching anything else.

Why Word sometimes won't let you change the case

If the text you're trying to change is inside a table, a text box, or a header or footer, the Aa button might be grayed out or not work the way you expect. This happens because Word treats those areas differently from regular document text. The workaround is to use Find and Replace instead, which usually works in those locations.

Text that's been formatted with ALL CAPS as a character style (not just typed in capitals) can also behave oddly. Word may convert it to lowercase, but the ALL CAPS formatting might stay applied underneath, so it looks like nothing changed. If this happens, select the text again and click the Aa button one more time, or remove the ALL CAPS formatting manually by going to Home > Font and unchecking the ALL CAPS box.

The other case options Word offers

The Aa dropdown menu gives you five choices: lowercase, UPPERCASE, Title Case, Sentence case, and tOGGLE cASE. Title Case capitalizes the first letter of each word, which is useful for headings. Sentence case capitalizes only the first letter of the sentence and proper nouns, which is the standard for body text. tOGGLE cASE flips whatever case each letter already has — capitals become lowercase and vice versa — which is rarely useful but sometimes handy for fixing text that got accidentally converted wrong.

You can switch between any of these options as many times as you want. Select the text, pick a different case from the menu, and Word applies it. There's no limit to how many times you can change your mind.

Keyboard shortcuts if you use Word frequently

If you work in Word every day, you can set up a keyboard shortcut to change case without using the menu. Go to File > Options > Customize Ribbon (or Quick Access Toolbar, depending on your version). Find the "Change Case" command in the list, select it, and assign it a key combination you'll remember. This is an advanced move and takes a few minutes to set up, but it saves time if you're converting text constantly.

Most people don't need this — the Aa button is fast enough for occasional use. But if you're editing a document with hundreds of capitalized words, a keyboard shortcut can speed things up.

Frequently Asked Questions

Can I change only part of a word to lowercase?

No. Word's case-change tools work on whole words or whole selections. If you select "HELLO" and choose lowercase, it becomes "hello" — you can't make it "hELLO" or "heLLo" using the Aa button. You'd have to type that manually or use Find and Replace with very specific text strings.

Does changing case affect the spelling checker?

No. Word's spelling checker looks at the letters themselves, not how they're capitalized. If "HELLO" is spelled correctly, "hello" is also correct. Changing case won't create new spelling errors or fix existing ones.

What if I'm using Google Docs instead of Word?

Google Docs has a similar feature. Highlight your text, go to Format > Text, and you'll see options for lowercase, UPPERCASE, and Title Case. The process is nearly identical to Word, just in a different menu location.

Can I undo a case change after I save the document?

Once you save and close a document, you can't undo changes from before you saved. But if you just saved and realized the mistake, you can close the document without saving again, then reopen it — it will revert to the last saved version. If you've already saved multiple times, you're stuck with the change unless you manually fix it or use Find and Replace to convert it back.