EJS vs Pug: What are the differences?

EJS (Embedded JavaScript) and Pug (formerly known as Jade) are both popular templating engines used in web development. Although they serve a similar purpose, there are several key differences between the two.

1. Syntax: One fundamental difference between EJS and Pug is their syntax. EJS uses a familiar HTML-like syntax, allowing developers to directly embed JavaScript code within the HTML markup. On the other hand, Pug uses a unique indentation-based syntax, relying on whitespace and indentation to define the structure of the code.

2. Code Readability: Due to its HTML-like syntax, EJS tends to be more readable for developers who are already familiar with HTML. Pug, on the other hand, can be more concise and compact due to its indentation-based syntax, but it may take some time for developers to get used to this unique syntax.

3. Tag and Attribute Syntax: EJS uses the standard HTML tag and attribute syntax, where tags are enclosed in angle brackets and attributes are specified using double quotes or single quotes. In contrast, Pug uses a simplified syntax for tags and attributes. Tags are specified by indentation, and attributes can be written in a shorthand format without the need for quotes or angle brackets.

4. Whitespace Handling: Another significant difference lies in how EJS and Pug handle whitespace. EJS preserves all the whitespace and indentation in the HTML markup, while Pug automatically removes unnecessary whitespace, resulting in a more compact HTML output.

5. Code Reusability: EJS allows developers to reuse HTML components easily due to its HTML-like syntax. By keeping the markup separate from the JavaScript, it becomes easier to reuse and maintain code. Pug, with its indentation-based syntax, also promotes code reusability by allowing developers to create reusable mixins and include them in multiple templates.

6. Error Handling: EJS provides detailed error messages that can help developers identify and fix issues in their code. It displays the line number and error message, making it easier to troubleshoot. Pug, on the other hand, can be less forgiving when it comes to syntax errors, as it requires strict adherence to its indentation-based syntax.

In summary, EJS offers familiar HTML-like syntax and detailed error handling, making it easier to learn and debug, but results in larger files. Pug, with its unique indentation and reusable mixins, leads to cleaner, more concise code, but requires a steeper learning curve and less forgiving error messages.