iloveepubBearbetas lokalt — filer lämnar aldrig din enhet
Byt EPUB-omslag
Byt omslag på vilken EPUB-bok som helst med några klick: det aktuella omslaget plockas fram automatiskt, du ser det nya bredvid det gamla i en förhandsvisning och allt annat i boken lämnas orört. Hela bytet sker lokalt i din webbläsare — boken laddas aldrig upp någonstans. Gratis, utan konton, utan gränser.
01Välj din EPUB
When the shelf tile is wrong and the book is fine
A public-domain EPUB whose cover is a 200 px thumbnail, soft on a 300 ppi e-ink screen. A draft you exported with a placeholder cover. A file that contains cover.jpg but never marks it, so Kindle and Kobo draw a gray tile and people assume the book is corrupt. Replacing the cover is a metadata job. The chapters do not need to be reflowed.
Amazon publishes 1600×2560 as the Kindle cover size it prefers, and a 2:3 portrait ratio is what most shelves crop toward. This page does not resize the image you supply. If the pixels matter, resize them before you upload. JPG is the safest type across Kindle, Kobo, and Apple Books. PNG is fine for flat art. WebP and GIF are accepted here. Older firmware may ignore WebP.
Which bytes change
The current cover is found from the EPUB 2 meta name=cover, or from an item with the EPUB 3 property cover-image. If the new file has the same extension, its bytes replace that image and the entry is stored, not deflated. If the extension changes, a new path is written, the old image is removed, and the manifest href and media-type are updated. Any img or SVG image whose source pointed exactly at the old path is retargeted. Chapter files that did not point at the cover are not edited.
Both markers are written: meta name=cover, and properties=cover-image. A book with no cover gets a new manifest item. That item is not inserted into the spine. Shelves read the markers. They do not need an extra chapter. Removing a cover deletes the image, the manifest item, the meta tag, and a cover page that became empty after its only image was removed. The shared repack writes mimetype first, stored uncompressed. The book cap is 120 MB.
What a cover swap leaves alone
Nothing is cropped to 2:3. A square image stays square, and some shelves letterbox or crop it themselves. A cover that is only the first page of a fixed-layout book, with no cover declaration and no image reference to update, is not detected as a cover. CSS background images are not hunted down.
Kindle caches thumbnails for a book it has already imported. The EPUB can already contain the new image while the device still shows the old tile, until you re-send the file by email, the Send to Kindle app, or USB. Title and author are not edited here. Use the metadata editor for those fields.
Calibre's metadata dialog goes further, and elsewhere
Calibre's Edit metadata can replace the cover and can also download one from online sources. It writes Calibre's own tags into the OPF. That download is useful when you do not have an image. It is also a network request this page never makes.
This tool swaps the image and the two cover markers, then repacks the zip. It does not add calibre: metadata and it does not contact a cover service. Use Calibre when you want a fetched cover or a library-wide metadata edit. Use this when the only change is an image you already have.
Så byter du omslag på en EPUB
Välj din EPUB-fil
Öppna boken från din enhet. Det aktuella omslaget plockas fram och visas — inget laddas upp.
Ladda upp det nya omslaget
Välj en JPG-, PNG-, WebP- eller GIF-bild och förhandsgranska den bredvid det gamla omslaget innan du bekräftar.
Ladda ner den uppdaterade EPUBen
Spara filen och kopiera den till din läsare — det nya omslaget dyker upp på hyllan och i boken.
Vanliga frågor
I uploaded a PNG and the old cover was a JPG. What changes in the zip?
The new image is stored under a new filename, the old image is removed, and the manifest href and media-type are updated. A cover page whose img pointed at the old path is retargeted. Chapter files that did not point at the cover are not edited.
The book had no cover. Do you add a title page?
No. A cover image is added to the manifest and marked with both meta name=cover and the cover-image property. It is not inserted into the reading order. Shelves read those markers.
Will the image be resized to 1600×2560?
No. Amazon publishes 1600×2560 as the Kindle cover size it prefers, and a 2:3 ratio avoids cropping on most shelves, but the pixels you upload are the pixels stored. Resize first if the exact dimensions matter.
Kindle still shows the old cover. Is the file wrong?
Kindle caches the thumbnail of a book it already imported. Re-send the file by email, the Send to Kindle app, or USB so the device reads the new image. The EPUB itself already has the replacement.
How is this different from Calibre's Edit metadata?
Calibre can replace the cover, download one from the internet, and write its own calibre tags into the OPF. This page never fetches a cover and does not add those tags. It updates the image, the manifest entry, and the two cover markers.