Guide
EPUB too big for Kindle? Here’s the fix
Send to Kindle refuses anything over 200MB. If your book just bounced off that wall, the good news is that oversized EPUBs are nearly always one specific, very fixable problem.
Why your EPUB is enormous
Text is tiny – a long novel's prose zips to well under a megabyte. When an EPUB weighs hundreds of megabytes, the weight is images: print-resolution photographs in a memoir, full-page scans in a cookbook, children's picture books exported at press quality, or covers saved as 20MB PNGs. Publishers and export tools routinely embed images at 4,000+ pixels wide. A Kindle Paperwhite's screen is 1,236 pixels wide. Every pixel beyond what the screen can show is dead cargo you're asking Amazon to reject.
The five-minute fix
- Open the Kindle EPUB fixer – it runs in your browser, so your book is never uploaded anywhere.
- Drop the rejected EPUB. You'll get a report: total size, how much is images, and which files are the offenders. Diagnosis first, surgery second.
- Click Fix all. Images are recompressed and capped at 1,920px on the long edge – comfortably above every Kindle screen – junk files from other apps are removed, and common metadata problems are repaired along the way.
- Compare the before/after sizes, download, and send it again.
Typical results on image-heavy books run 60–90% smaller. A 480MB scanned cookbook lands around 40–80MB; a photo-stuffed memoir usually drops under 20MB.
“Won’t compressing ruin my images?”
Not where you'll ever see it. E-ink displays show 16 shades of grey at around 300ppi; even the colour Kindles top out far below print resolution. Recompressing a 4,000px image to 1,920px at high JPEG quality is invisible on the device you're sending it to – the pixels being discarded were never displayable there in the first place. Your original file stays untouched on your machine, so nothing is lost even in principle. And the fixer treats the book's text as read-only: not one character is altered, ever.
Still over the limit?
Rare, but it happens with 1,000-page art books. Your options, in order: send over
USB instead (sideloading has no size cap – plug in, copy to the
documents folder); split the book into volumes; or accept a lower quality
setting for the truly gigantic scans. And if the file that's too big is a comic archive
rather than an EPUB, convert it with the CBZ to PDF tool's
“small” preset instead – same idea, built for comics.
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One more reason to fix this locally: an EPUB that's too big for Amazon is also miserable to upload to a conventional converter site – you'd spend twenty minutes feeding your 400MB book to a stranger's server to solve a problem your own browser can fix in seconds. That's the whole point of ebook.tools.