# Generating eBooks and PDFs

GitBook can generates a website, but can also output content as ebook (ePub, Mobi, PDF).

```
# Generate a PDF file
$ gitbook pdf ./ ./mybook.pdf

# Generate an ePub file
$ gitbook epub ./ ./mybook.epub

# Generate a Mobi file
$ gitbook mobi ./ ./mybook.mobi
```

### Installing ebook-convert

`ebook-convert` is required to generate ebooks (epub, mobi, pdf).

##### GNU/Linux

Install the [Calibre application](https://calibre-ebook.com/download).

```
$ sudo aptitude install calibre
```

In some GNU/Linux distributions node is installed as nodejs, you need to manually create a symlink:

```
$sudo ln -s /usr/bin/nodejs /usr/bin/node
```

##### OS X

Download the [Calibre application](https://calibre-ebook.com/download). After moving the `calibre.app` to your Applications folder create a symbolic link to the ebook-convert tool:

```
$ sudo ln -s ~/Applications/calibre.app/Contents/MacOS/ebook-convert /usr/bin
```

You can replace `/usr/bin` with any directory that is in your $PATH.

### Cover

Covers are used for all the ebook formats. You can either provide one yourself, or generate one using the [autocover plugin](https://plugins.gitbook.com/plugin/autocover).

To provide a cover, place a **`cover.jpg`** file at the root directory of your book. Adding a **`cover_small.jpg`** will specify a smaller version of the cover. The cover should be a **JPEG** file.

A good cover should respect the following guidelines:

* Size of 1800x2360 pixels for `cover.jpg`, 200x262 for `cover_small.jpg`
* No border
* Clearly visible book title
* Any important text should be visible in the small version