PDF text too small on an e-reader
A PDF can't make its letters bigger, because each page is a fixed picture shrunk to fit your screen. The fixes are to show less page (crop, landscape, zoom), make the strokes darker so they read at a smaller size, or use a bigger screen.
Key takeaways
- A PDF keeps the printed page's shape. Your e-reader scales the whole page, margins included, to fit the screen, so the text can only be as big as that allows.
- An A4 page on a 6-inch screen shows at about 41% of its printed size, so 10-point type reads like 4-point.
- Landscape mode and zoom help without changing the file, at the cost of scrolling on every page.
- Cropping the margins once for the whole book is the only fix that makes every page bigger with no scrolling.
- Grey, thin print looks smaller than it is. Turning it solid black on white makes the same size easier to read.
Why the text is so small
When you read an EPUB or a Kindle book, the reader lays out the words for your screen and you choose the size. A PDF doesn’t let it. The PDF says “this is a page, this shape, with these things in these places”, and the reader’s only option is to make the whole page fit.
For a scanned book it’s stricter still. There’s no text in the file, just a photo of each page, so even a reader that could reflow typed PDFs has nothing to reflow.
How small, in numbers
Take a 6-inch e-reader screen with a 3:4 shape. That works out at about 91 mm wide and 122 mm tall. An A4 page is 210 × 297 mm.
- The page is taller in proportion than the screen, so its height decides the scale: 122 ÷ 297 is about 0.41.
- Everything on the page shows at 41% of its printed size. Type printed at 10 point reads like 4 point.
- A 6 × 9 inch paperback page does better, at about 53%, because it starts closer to the screen’s size.
Bigger screens move the number: the same A4 page on a 10-inch screen of the same shape comes out at about 69%. These are worked out from page and screen sizes, not measured on a device, but the reasoning holds for any reader.
The fixes, from free to permanent
| Fix | What it costs you | Changes the file |
|---|---|---|
| Landscape mode | Scrolling down every page | No |
| Zoom and pan | Moving round every page | No |
| Crop the margins | One crop for the book | Yes |
| Black text on white | Nothing visible | Yes |
| Bigger screen | A new device | No |
| Convert to EPUB | Often lost lines, moved footnotes, lost page numbers | Yes, into a different book |
Landscape and zoom
Turning the reader sideways fits the page’s width to the long side of the screen. The text grows, and you scroll down through each page in two or three steps. Zoom goes further and has you panning in two directions. Kobo’s help describes zoom and pan for PDFs through the reading menu or a pinch. We haven’t checked the menus on other readers. Both are fine for a reference look-up. Over a 300-page novel, it gets tiring.
Cropping
Margins, the scanner’s dark edge and the shadow at the spine all get scaled down along with the text. Cut them away and the printed area becomes the page, so it fills more of the screen with no scrolling. How much bigger depends on how wide the margins were: on a scan with a lot of border, the difference is easy to see. A single crop drawn over the whole book keeps every page at the same scale, so the text size doesn’t jump as you turn. The crop page goes through how to set one.
Darker strokes
Small text you can read on paper often fails on screen because it is thin and grey. On e-ink, grey print on grey paper has little contrast, and thin strokes break up. The same letters turned solid black on white read clearly at a smaller size. This doesn’t change the size; it changes how small you can comfortably go.
A bigger screen
If you read mostly large-format books, such as A4 textbooks, music or magazines, the screen size is the hard limit. Before you buy one, fix the file: a cropped, cleaned PDF reads better on the device you already own, and on any you buy next.
EPUB conversion
Converting rebuilds the book from its text so it can reflow. A scan has no text until OCR adds it, and even then, Calibre’s manual warns that complex, multi-column and image-based PDFs aren’t supported well. Expect missing lines, footnotes in the middle of paragraphs, and page numbers that no longer match the printed book.
What we’d do with a scanned book
- Crop the margins for the whole book in one go.
- Clean the pages so the paper is white and the print is black.
- Add searchable text, so you can find your place and look up words.
- Read it in portrait. If a page is still too small, use landscape for that book only.
FixMyScan does the first three in one upload and gives you back a PDF for any reader.
Questions
How do I make PDF text bigger on Kindle?
You can't change the font of a PDF the way you can with a Kindle book. You can zoom or turn to landscape where your model offers it (we haven't checked every Kindle), or crop the PDF's margins before sending it, which makes the page itself fill more of the screen.
Why can't I change the font size of a PDF?
A PDF fixes where everything sits on the page. A scanned PDF goes further: there are no letters at all, only a picture of the page. The reader can scale the picture, not reset the type.
Can I zoom in on a PDF on my Kobo?
Yes. Kobo's help says you can zoom and pan a PDF through the reading menu or by pinching. You then move round each page to read it.
Should I convert the PDF to EPUB so the text reflows?
For a typed PDF it can work. For a scanned book, conversion often drops lines, scrambles columns and moves footnotes into the text. See scanned PDF or EPUB for when each makes sense.
Which e-reader is best for small PDF text?
A bigger screen helps more than anything else about the device. A 10-inch screen shows an A4 page at roughly two-thirds size, a 6-inch at under half. Whatever you buy, a cropped page reads bigger on it.
Will cropping cut off part of my book?
Not if you set the box outside the printed area. FixMyScan shows 50 pages stacked so you can see where the text sits across the book before you crop.
Does FixMyScan change the font?
No. It keeps your pages as they were printed, crops the margins, and makes the paper white and the print black. The type is the book's own.