Change font size in three taps on any Kindle device or app

On a Kindle e-reader or the Kindle app, you adjust font size by opening a book, tapping the middle of the screen, and selecting the font icon (usually marked with an "A" symbol). From there, you can slide left to make text smaller or right to make it larger. The change takes effect immediately and stays set for that book — if you switch to another book, you can adjust its size independently.

The exact steps differ slightly between Kindle devices and the Kindle app on phones or tablets, but the principle is the same. You do not need to restart the book or change any settings outside of the reading screen.

Key Takeaways

  • Font size adjustments happen inside the book itself, not in device settings, and take effect instantly.
  • Each book remembers its own font size setting, so changing one book does not affect others you are reading.
  • Kindle e-readers and Kindle apps on phones or tablets use the same method but may have slightly different button locations.
  • You can also change font style, line spacing, and margins from the same menu where you adjust size.

Steps on a Kindle e-reader or Paperwhite

Open the book you want to read. Tap the center of the screen — a toolbar will appear at the top and bottom. Look for the font icon, which shows an "A" with a line underneath. Tap it to open the font menu.

In the font menu, you will see a slider with an "A" on the left (smaller) and an "A" on the right (larger). Slide your finger left to decrease the size or right to increase it. The text on the page updates as you move the slider, so you can see the change in real time. Once you find a size you like, tap outside the menu or press the back button to close it and return to reading.

Steps on the Kindle app for iPhone, iPad, or Android

Open the book and tap the center of the screen. A menu bar appears at the top. Look for the "Aa" icon (two A's stacked or side by side) and tap it. This opens the text settings panel.

You will see a slider labeled with an "A" on each end. Drag the slider to the right to enlarge the text or to the left to shrink it. The page refreshes to show your new size. Tap outside the panel or swipe down to close it and continue reading.

What happens to your font size setting

Kindle remembers the font size you choose for each individual book. If you set one book to a larger size and then open a different book, that second book will use whatever size you last set for it — not the size from the first book. This means you can read one book at size 4 and another at size 6 without having to reset every time you switch.

If you buy a new Kindle device or reinstall the Kindle app, your font size preferences sync across devices if you are signed into the same Amazon account. The settings travel with your library.

Other text adjustments in the same menu

The font menu also lets you change the typeface itself. Kindle offers several fonts — typically options like Caecilia, Palatino, and Georgia — and you can switch between them the same way you adjust size. Some readers prefer serif fonts (with small lines at the ends of letters) while others like sans-serif (without those lines).

You can also adjust line spacing and margins from this menu. Line spacing controls how much room sits between lines of text, and margins control how much white space appears on the left and right edges of the page. Both can make reading more comfortable depending on your preference and eyesight.

Why the font size might not change

If you tap the center of the screen and no menu appears, the book may be in full-screen mode. Try tapping again or swiping down from the top of the screen. On some older Kindle devices, you may need to press a physical button instead of tapping the screen — check your device manual if the tap method does not work.

If the font size slider appears but does not move when you drag it, try closing the book completely and reopening it. Occasionally the app or device needs to refresh. If the problem persists, restart the Kindle device or close and reopen the Kindle app on your phone or tablet.

Frequently Asked Questions

Can I set a default font size for all my books?

No. Kindle does not offer a global default that applies to every book you read. Each book keeps its own size setting. However, once you choose a size for one book, you can use that same size for the next book by adjusting it the same way — Kindle will remember that choice for the second book independently.

Does changing font size affect how many pages the book has?

Yes. When you increase the font size, the same text spreads across more pages because fewer words fit on each screen. The page count shown in your Kindle will change to reflect this. The actual content of the book does not change — only how it displays.

What is the largest font size available?

Kindle offers several size levels, typically ranging from very small to quite large. The exact number of steps depends on your device or app version, but most readers find the largest setting readable even from across a room. If the largest Kindle size is still too small, check whether your device has a system-wide text size setting in its accessibility options.

Will my font size setting stay the same if I lend my book to someone?

When you lend a Kindle book to another person, they receive it with the default font size, not the size you were reading at. Your personal reading settings do not transfer with the loan. The borrower can adjust the size to their own preference, and when the book returns to you, your original setting will be there waiting.