Smarty is a template engine for PHP, facilitating the separation of presentation (HTML/CSS) from application logic.

View the Project on GitHub smarty-php/smarty


Some of Smarty’s features:

Separation of presentation from application code

How does it work?

Under the hood, Smarty “compiles” (basically copies and converts) the templates into PHP scripts. This happens once when each template is first invoked, and then the compiled versions are used from that point forward. Smarty takes care of this for you, so the template designer just edits the Smarty templates and never has to manage the compiled versions. This approach keeps the templates easy to maintain, and yet keeps execution times extremely fast since the compiled code is just PHP. And of course, all PHP scripts take advantage of PHP op-code caches such as APC.

Template Inheritance

Template inheritance was introduced in Smarty 3. Before template inheritance, we managed our templates in pieces such as header and footer templates. This organization lends itself to many problems that require some hoop-jumping, such as managing content within the header/footer on a per-page basis. With template inheritance, instead of including other templates we maintain our templates as single pages. We can then manipulate blocks of content within by inheriting them. This makes templates intuitive, efficient and easy to manage. See Template Inheritance for more info.

Why not use XML/XSLT syntax?

There are a couple of good reasons. First, Smarty can be used for more than just XML/HTML based templates, such as generating emails, javascript, CSV, and PDF documents. Second, XML/XSLT syntax is even more verbose and fragile than PHP code! It is perfect for computers, but horrible for humans. Smarty is about being easy to read, understand and maintain.

Template Security

Although Smarty insulates you from PHP, you still have the option to use it in certain ways if you wish. Template security forces the restriction of PHP (and select Smarty functions.) This is useful if you have third parties editing templates, and you don’t want to unleash the full power of PHP or Smarty to them.


Sometimes Smarty gets compared to Model-View-Controller (MVC) frameworks. Smarty is not an MVC, it is just the presentation layer, much like the View (V) part of an MVC. As a matter of fact, Smarty can easily be integrated as the view layer of an MVC. Many of the more popular ones have integration instructions for Smarty, or you may find some help here in the forums and documentation.

Other Template Engines

Smarty is not the only engine following the “Separate Programming Code from Presentation” philosophy. For instance, Python has template engines built around the same principles such as Django Templates and CheetahTemplate. Note: Languages such as Python do not mix with HTML natively, which give them the advantage of proper programming code separation from the outset. There are libraries available to mix Python with HTML, but they are typically avoided.

What Smarty is Not

Smarty is not an application development framework. Smarty is not an MVC. Smarty is not an alternative to Laravel, Symfony, CodeIgniter, or any of the other application development frameworks for PHP.

Smarty is a template engine, and works as the (V)iew component of your application. Smarty can easily be coupled to any of the engines listed above as the view component. No different than any other software, Smarty has a learning curve. Smarty does not guarantee good application design or proper separation of presentation, this still needs to be addressed by a competent developer and web designer.

Is Smarty Right for Me?

Smarty is not meant to be a tool for every job. The important thing is to identify if Smarty fits your needs. There are some important questions to ask yourself:

Template Syntax

Are you content with PHP tags mixed with HTML? Are your web designers comfortable with PHP? Would your web designers prefer a tag-based syntax designed for presentation? Some experience working with both Smarty and PHP helps answer these questions.

The Business Case

Is there a requirement to insulate the templates from PHP? Do you have untrusted parties editing templates that you do not wish to unleash the power of PHP to? Do you need to programmatically control what is and is not available within the templates? Smarty supplies these capabilities by design.

Feature set

Does Smarty’s features such as caching, template inheritance and plugin architecture save development cycles writing code that would be needed otherwise? Does the codebase or framework you plan on using have the features you need for the presentation component?

Sites using Smarty

Many well-known PHP projects make use of Smarty such as XOOPS CMS, CMS Made Simple, Tiki CMS/Groupware and X-Cart to name a few.


Whether you are using Smarty for a small website or massive enterprise solution, it can accommodate your needs. There are numerous features that make Smarty a great choice: