Troubleshooting decision tree

Send to Kindle not working? Start with the failed step

“Not working” can mean the website refuses the file, Amazon rejects it later, the book never appears, or the book arrives with a grey cover. Those symptoms need different fixes.

Changing the EPUB before you know which step failed can waste time. Send to Kindle has several stages: your browser or app accepts the file, Amazon processes it, the document is added to the correct library, a device syncs it, and Kindle renders its cover and contents. Record the exact message and identify the last stage that succeeded.

1. The file will not upload

If the progress bar never starts or the page reports a network error immediately, test the service and browser before editing the book. Confirm that the file has an .epub extension, choose it again from local storage, disable an interfering browser extension, and retry in a private window or another supported browser. Amazon’s official Send to Kindle page lists the currently accepted formats and size limit.

If several unrelated files fail in the same way, the EPUB is unlikely to be the common cause. Check your connection, account session and the service again later.

2. The upload completes, then delivery fails

This is the strongest signal that the file needs inspection. Amazon has received it but could not complete conversion. Common EPUB-level causes include malformed XML, a broken META-INF/container.xml, a missing package document, manifest entries that point to absent files, spine references with no matching item, or a badly rebuilt ZIP container.

Do not simply rename the file or repeatedly upload it. Run a structural check, fix only the proven fault, rebuild the EPUB and open the repaired copy locally before resending. Our rejected EPUB guide explains this path in detail.

3. Amazon says delivery succeeded, but the book is missing

First verify that the receiving Kindle app or device uses the same Amazon account. Then open the library, switch from Downloaded to All, clear any document or book filter, connect to Wi-Fi and sync. A personal document can be present in the cloud library without being downloaded to a particular device.

If you used email, also verify the destination address and the approved sender address in your Amazon account. If the item is still processing, wait before resending: multiple copies make later diagnosis harder.

4. The book arrives, but the cover is grey or blank

Delivery succeeded, so this is not a general Send to Kindle outage. Check whether the EPUB contains a cover image and whether the OPF manifest identifies it correctly. EPUB 3 uses the cover-image property; EPUB 2 commonly uses a metadata reference to the cover item ID. The file path, capitalization and media type must also agree.

A stale library thumbnail can survive a repair. Remove the older personal document, allow the deletion to sync, and then send the repaired copy. See the dedicated no-cover troubleshooting guide.

5. The book opens, but navigation or text is broken

A successful delivery does not prove that every resource is healthy. Wrong character encoding, invalid XHTML, missing fonts, broken navigation files or incorrect spine order can survive one stage and fail at reading time. Validate the EPUB and inspect the first failing resource rather than converting the book through several unrelated formats.

A clean retest

1. Save the exact status or email message.
2. Test one known-good EPUB to separate service and file causes.
3. Make one repair at a time.
4. Open the rebuilt file in a reading app.
5. Remove any failed duplicate from the Kindle library.
6. Upload once and wait for a clear result.

Sources

• Amazon Send to Kindle
• W3C EPUB 3.3