* Downloading an archive file from [yiiframework.com](http://www.yiiframework.com/download/).
The first approach is highly recommended, as it allows you to automatically install updates
You can install Yii in two ways, using [Composer](http://getcomposer.org/) or downloading an archive file.
The former is the preferred way as it allows you to install new [extensions](structure-extensions.md)
or update Yii by running a single command.
Installing via Composer
-----------------------
The recommended way to install Yii is to use the [Composer](http://getcomposer.org/) package manager. If you do not already
have Composer installed, you may download it from [http://getcomposer.org/](http://getcomposer.org/), or run the following command to download and install it:
```
curl -s http://getcomposer.org/installer | php
```
(It is strongly recommended to perform a [global Composer installation](https://getcomposer.org/doc/00-intro.md#globally)).
For problems with, or more information on, installing Composer, see the official Composer guide:
With Composer installed, you can create a new Yii site using one of Yii's ready-to-use application templates. Based on your needs, choosing the right template can help bootstrap your project.
Currently, there are two Yii application templates available:
-[Basic Application Template](https://github.com/yiisoft/yii2-app-basic), a basic frontend application template
-[Advanced Application Template](https://github.com/yiisoft/yii2-app-advanced), consisting of a frontend, a backend, console resources, common (shared code), and support for environments
For template installation instructions, see the above linked pages.
To read more about the ideas behind these application templates and the proposed usage,
refer to the [basic application template](apps-basic.md) and [advanced application template](apps-advanced.md) documents.
If you do not want to use a template, rather starting from scratch, you'll find information in the [creating your own application structure](apps-own.md) document. This approach is only recommended for advanced users.
Installing from zip
-------------------
Installation from a zip file involves two steps:
1. Downloading an application template from [yiiframework.com](http://www.yiiframework.com/download/).
2. Unpacking the downloaded file.
If you do not already have Composer installed, you may get it by following the instructions at
[getcomposer.org](https://getcomposer.org/download/), or simply
If you only want the Yii Framework files you can download a zip file directly from [github](https://github.com/yiisoft/yii2-framework/releases).
To create your application you might want to follow the steps described in [creating your own application structure](apps-own.md).
This is only recommended for advanced users.
* on Linux or Mac, run the following commands:
> Tip: The Yii framework itself does not need to be installed under a web-accessible directory (in fact, it should not be).
A Yii application has one entry script, which is usually the only file that absolutely must be
exposed to web users (i.e., placed within the web directory). Other PHP scripts, including those
in the Yii Framework, should be protected from web access to prevent possible exploitation by hackers.
```
curl -s http://getcomposer.org/installer | php
mv composer.phar /usr/local/bin/composer
```
* on Windows, download and run [Composer-Setup.exe](https://getcomposer.org/Composer-Setup.exe).
Please refer to the [Composer Documentation](https://getcomposer.org/doc/) if you encounter any
problems or want to learn more about the Composer usage.
Requirements
------------
Yii 2 requires PHP 5.4.0 or higher. Yii has been tested with the [Apache HTTP server](http://httpd.apache.org/) and
[Nginx HTTP server](http://nginx.org/) on both Windows and Linux.
Yii may also be usable on other web servers and platforms, provided that PHP 5.4 or higher is present.
After installing Yii, you may want to verify that your server satisfies
Yii's requirements. You can do so by running the requirement checker
script in a web browser or from the command line.
If you have installed a Yii application template via the downloaded zip file or Composer, you'll find a `requirements.php` file in the
base directory of your application.
In order to run this script on the command line use the following command (after navigating to the directory where `requirements.php` can be found):
With Composer installed, you can install Yii by running the following command under a Web accessible folder:
In order to run this script in your browser, you must make sure it's within a web directory, and then
access `http://hostname/path/to/yii-app/requirements.php` in your browser.
> Note: This section is under development.
The above command installs Yii as a directory named `basic`.
The basic Yii application template is a perfect fit for small projects or when you're just learning the framework.
The basic application template includes four pages: a homepage, an about page, a contact page, and a login page.
The contact page displays a contact form that users can fill in to submit their inquiries to the webmaster. Assuming the site has access to a mail server and that the administrator's email address is entered in the configuration file, the contact form will work. The same goes for the login page, which allows users to be authenticated before accessing privileged content.
> Tip: If you want to install the latest development version of Yii, you may use the following command
Now set document root directory of your Web server to /path/to/yii-application/web and you should be able to access the application using the URL `http://localhost/`.
Other Installation Options
--------------------------
Directory structure
-------------------
The above installation instructions show how to install Yii in terms of a basic Web application that works out of box.
It is a good start for small projects or if you just start learning Yii.
The basic application does not divide application directories much. Here's the basic structure:
There are other installation options available:
-`assets` - application asset files.
-`AppAsset.php` - definition of application assets such as CSS, JavaScript etc. Check [Managing assets](assets.md) for
details.
-`commands` - console controllers.
-`config` - configuration.
-`controllers` - web controllers.
-`models` - application models.
-`runtime` - logs, states, file cache.
-`views` - view templates.
-`web` - webroot.
* If you only want to install the core framework and would like to build an application from scratch,
you may follow the instructions as explained in [Building Application from Scratch](tutorial-start-from-scratch.md).
* If you want to start with a more sophisticated application that supports team development environment,
you may consider [Advanced Application Template](tutorial-advanced-app.md).
Root directory contains a set of files.
-`.gitignore` contains a list of directories ignored by git version system. If you need something never get to your source
code repository, add it there.
-`codeception.yml` - Codeception config.
-`composer.json` - Composer config described in detail below.
-`LICENSE.md` - license info. Put your project license there. Especially when opensourcing.
-`README.md` - basic info about installing template. Consider replacing it with information about your project and its
installation.
-`requirements.php` - Yii requirements checker.
-`yii` - console application bootstrap.
-`yii.bat` - same for Windows.
Verifying Installation
----------------------
After installation, you can use your browser to access the installed Yii application with the following URL,
assuming you have installed Yii in a directory named `basic` that is under the document root of your Web server,
### config
```
http://localhost/basic/web/index.php
```
This directory contains configuration files:
You should see a "Congratulations!" page in your browser. If not, please check if your PHP installation satisfies
Yii's requirements by using one of the following approaches:
