iloveepubProcessed locally — files never leave your device
Replace EPUB Fonts
Embedded fonts are the heaviest thing in many EPUBs — a single CJK typeface can outweigh the entire text — and they can carry licensing questions you never agreed to. Remove them all and let your reader's fonts take over, or swap every embedded font for a file you choose, while the book's styling keeps working. All in your browser; nothing uploaded. Free.
01Select your EPUB
How to replace EPUB fonts
Select your EPUB file
Open the book from your device. Its embedded fonts are listed with file sizes — all read locally.
Remove or upload
Remove every embedded font to fall back to your reader's defaults, or upload a TTF/OTF/WOFF/WOFF2 file to take their place.
Download the updated EPUB
Save the file — same styling rules, new font reality behind them, and a smaller file if you removed.
Why swap embedded fonts
Size: a full Chinese or Japanese typeface adds tens of megabytes to a book. Licensing: commercial fonts embedded in pirated or converted ebooks put the reader in a gray zone. Rendering: ancient fonts sometimes confuse older reader firmware.
Removing the fonts lets your reader's own typography take over — on e-ink devices that usually means faster rendering and cleaner subpixel behavior.
How replacement keeps the book intact
Books reference fonts through CSS @font-face rules by family name. Replacement keeps every family name and points each rule at your file instead — so headings stay bold, body text stays serif, and no stylesheet is rewritten.
Frequently asked questions
Why would I remove fonts from an EPUB?
File size (CJK fonts are huge), licensing hygiene, and rendering quirks on older readers. Text then uses your reader's default font.
After replacing, does the whole book use my font?
Yes — every @font-face rule is pointed at your file, so every element that asked for an embedded font now renders with yours.
Which font formats are supported?
TTF, OTF, WOFF and WOFF2. WOFF2 is the smallest; TTF is the most universally accepted by reader firmware.
What font do I get after removing everything?
Your reader's default — which is what most e-ink users prefer anyway: crisper, faster, and consistent with the rest of the library.
Am I allowed to embed any font I upload?
You are responsible for the files you use. Open-license fonts (SIL OFL typefaces like Source Han Serif, or Charter) are safe for personal embedding; commercial fonts need their license.
Is my book uploaded to a server?
Never. Fonts are swapped entirely in your browser — zero uploads, verifiable in the network inspector.