Change text size in three steps on any Kindle device
On any Kindle e-reader or Kindle app, you can make text larger or smaller without leaving your book. Open the book you're reading, tap the middle of the screen to bring up the toolbar, then tap the font icon (it looks like "A" with an up or down arrow). Slide the bar left to shrink text or right to enlarge it. The change takes effect immediately and stays set for that book.
The exact location of controls varies slightly between Kindle devices and the Kindle reading app on phones and tablets, but the principle is the same: tap to reveal the toolbar, find the text size control, and adjust. You don't need to restart your book or change any settings outside the reading screen.
Key Takeaways
- Text size adjusts from within your book using the toolbar — tap the middle of the screen to make it appear.
- The font icon shows an "A" with arrows; drag the slider to make text larger or smaller instantly.
- Your chosen size stays set for that individual book, but you can change it again anytime.
- Kindle e-readers and Kindle apps on phones and tablets all have text size controls, though their exact placement differs slightly.
- Text size changes do not affect how far through the book you are — your location stays the same.
Text size on Kindle e-readers (Paperwhite, Oasis, Basic)
On a physical Kindle e-reader, open any book and tap the center of the screen. A toolbar appears at the top and bottom. Look for the font icon in the toolbar — it shows the letter "A" with a small up arrow and a large down arrow next to it. Tap this icon to open the text size menu.
A slider bar appears showing sizes from smallest to largest. Drag the slider to the right to enlarge text, or to the left to make it smaller. The page reflows immediately to show your new choice. Close the toolbar by tapping elsewhere on the page, and keep reading. Your size preference stays set for that book even if you close and reopen it later.
Text size in the Kindle app on phones and tablets
On an iPhone, iPad, or Android phone running the Kindle app, open your book and tap the center of the screen. The toolbar appears at the top. Tap the font icon — again, an "A" with arrows — and a menu slides up from the bottom showing text size options.
Drag the slider left or right to adjust. You can also change the font style, line spacing, and margins from this same menu if you want. The changes take effect as soon as you adjust the slider. Tap outside the menu to close it and return to reading.
Text size on Kindle for Mac and Windows
If you read on a computer using Kindle Cloud Reader or the Kindle desktop app, open your book and look for the font icon in the toolbar at the top of the screen. Click it to open the text size slider. Drag left to shrink or right to enlarge, just as you would on a phone or tablet.
You can also use keyboard shortcuts: press Ctrl and + (plus) to enlarge, or Ctrl and − (minus) to shrink on Windows. On Mac, use Command and + or Command and −. These shortcuts work in most Kindle reading apps.
Why your text size choice stays with one book
Kindle stores your text size preference separately for each book. If you set a book to large text and then open a different book, that new book may start at a different size — usually the default. This happens because each book's formatting is independent. You can change the size in the new book the same way, and it will remember that choice for future reading sessions.
If you want all your books to start at the same size, you'll need to adjust each one individually. There is no global default setting across all Kindle books, though some reading apps let you set a preference that new books will use as a starting point.
Other text formatting options beyond size
While adjusting text size, you can also change the font itself. Tap or click the font icon and look for font name options — Kindle offers several choices like Bookerly, Caecilia, and others. Some fonts are easier to read at smaller sizes, and personal preference varies widely.
You can also adjust line spacing and margins from the same menu on most devices. Wider margins and more space between lines can make reading easier, especially at larger text sizes. These changes don't affect your reading progress or how the book is stored — they're purely visual adjustments you control.
Text size doesn't work the same way on all Kindle books
Most Kindle books are formatted to reflow, meaning the text adjusts to fit whatever size you choose. However, some books — particularly graphic novels, children's books with illustrations, and textbooks — are fixed-layout. In these books, text size controls may not work, or they may only zoom in and out rather than reflow the text around the page.
If you open a book and the text size slider is grayed out or missing, the book is likely fixed-layout. You can still zoom in by pinching on a touchscreen device, but the text won't reflow. Check the book's product page on Amazon to see if it notes "fixed layout" before you purchase if text size control is important to you.
Frequently Asked Questions
Will changing text size affect my bookmarks or notes?
No. Bookmarks, highlights, and notes stay exactly where you placed them, regardless of what text size you're using. The location in the book doesn't change when you adjust text size — only how the words appear on screen.
Can I set a default text size for all new books?
Not globally across all Kindle books. However, some Kindle apps remember the last size you used and apply it to the next book you open. The easiest approach is to adjust each book to your preferred size when you start reading it.
What if the text size slider isn't showing up?
The book may be fixed-layout, which means text size controls don't apply. Try tapping the screen again to make sure the toolbar appeared, or close and reopen the book. If the slider still doesn't appear, the book's format doesn't support reflowing text.
Does text size affect battery life on my Kindle e-reader?
No. Larger text doesn't drain the battery faster on an e-ink Kindle device. The battery life depends on how often you turn pages and use wireless features, not on the size of the text displayed.
Can I change text size while reading in airplane mode?
Yes. Text size is a local display setting that works offline. You can adjust it anytime, whether your Kindle is connected to the internet or not.