You don't need a cable to put a book on a Kindle. A cable is the oldest way and the least convenient: you need the right port, a computer nearby and, on newer models, an Amazon app just to see the drive. Here are the four wireless options, and which one suits which situation.
One condition applies to all of them: the book can't have DRM. Public-domain books, files an author gives you and ones you converted yourself are fine. A book bought in another store usually is not. Amazon rejects protected files, which is how books from other stores usually come.
1. Amazon's Send to Kindle website
Go to amazon.com/sendtokindle, sign in with the account your Kindle uses and drag the file onto the page. Amazon converts it and the book shows up on the Kindle the next time it has wifi.
Pick it when you're happy to have the book in your Amazon account and you have a computer or phone handy. It takes EPUB and PDF up to 200 MB. Step by step, with the error codes: how to send an EPUB to your Kindle.
2. By email
Every Kindle has an @kindle.com address. Email the book there from an address you've approved in your Amazon account.
Pick it when you're already in your mail and the file is small: the limit is 50 MB a message. It needs one-off setup (the approved senders list), and if the sender isn't on it, Amazon silently discards the message.
3. From the Kindle's own browser
Many e-ink Kindles have an "experimental browser". Open it, go to pecia.app/enviar, and the Kindle shows a four-character key. On your phone, open the upload page, type the key and pick the book. A link appears on the Kindle; tap it and confirm the download.
Pick it when you don't want to involve your Amazon account, or the book is on your phone and you want it on the Kindle in a minute. We convert an EPUB to the Kindle's format on the way, and a PDF too (more on that in how to send a PDF to your Kindle). It's free and needs no account, but only works if your model has the browser, and files are capped at 15 MB.
4. The Kindle app, on a phone or tablet
The Kindle app also takes books from Send to Kindle, so anything you send from the website or by email appears there too.
Pick it when you read on a phone, not on an e-ink Kindle. It's the same Amazon route as option 1.
Which one?
| You have | Use |
|---|---|
| A computer and a few minutes | The Send to Kindle website |
| The book in your inbox | |
| The book on your phone, and a Kindle with a browser | Send it from your phone |
| A PDF you want to read comfortably | Convert it first |
If the Kindle says it can't open the file, it may just be the format: see why a Kindle won't open an EPUB. And if you have a Kobo instead, you can send books to it from your phone too.