Thymeleaf Interview Questions & Answers (2025)

Thymeleaf is a server-side modern Java template engine that is used for both the development of web and standalone environments. It brings elegant natural templates to your development workflow which can be displayed correctly in the browsers and works as static prototypes. This workflow brought by Thymeleaf allows for stronger collaboration in the development teams.

Some of the major features in Thymeleaf are,

• It works for both web and non-web environments. With Thymeleaf, there is no hard dependency on the Servlet API.
• It has full and extensible internalization support.
• It is easily configurable.
• It has a high performance parsed template cache which reduces the input/output to the minimum.
• Thymeleaf has complete documentation available including several example applications. Several template modes of thymeleaf are XML, XHTML, and HTML5.

The Thymeleaf is written in Java programming language.

Some companies that use thymeleaf are

• Broadleaf Commerce,
• Auchan,
• Apereo CAS,
• Connect Group,
• Enerko Informatik,
• Enonic,
• Lagerwey,
• PPI AG,
• Trabe,
• Travelcompositor,
• VEDA GmbH,
• YobiDrive, and Sahibinden.com.

Thymeleaf allows you to process six kinds of templates by default. This is called as the Template mode in the Thymeleaf.

The templates processed by the thymeleaf are HTML, XML, TEXT, JAVASCRIPT, CSS, and RAW.

The HTML template mode allows you to process any kind of HTML input like the HTML5, HTML4, and XHTML. Likewise,

The XML template mode allows you to process the XML input.

The TEXT template allows you to use a special syntax for templates of non-markup nature.

The JAVASCRIPT and CSS template modes allow you to process JavaScript and CSS files in the Thymeleaf application.

The RAW template mode is used for inserting untouched resources.

A fragment is a part of the Thymeleaf template. You can import a part of the template(fragment) to other templates so it allows you to reuse some common parts of a site. To reuse fragments and import it, you have to describe the position of the fragment that you want to import.

With a dialect, you can build layouts and reusable templates in order to improve the code reuse.

Some features of the Thymeleaf dialects are Processing logic, Preprocessing & Postprocessing logic, and Expression objects.

The preprocessing logic is specified via processors that apply to the attributes in our tags.

The preprocessing & Postprocessing logic is specified using the pre and postprocessors that apply to our template before and after processing actually take place.

The Expression objects can be used in Thymeleaf standard expressions in order to perform the specialized operations we need.

The templates process in thymeleaf out-of-the-box are the HTML, XML, TEXT, JAVASCRIPT, CSS, and RAW.

You can use the "th:text=#{variable}" to print a variable in the Thymeleaf.

Thymeleaf allows you to completely decouple the template markup from its logic to allow for the creation of the completely logic-less markup templates in the HTML and XML template modes. The idea with the decoupled template logic is to define a separate file for the template logic with the ".th.xml" extension that lives in the same folder as the main HTML file.