How do I use EJS with Express.js?

After installing EJS via npm, set it as the view engine in your Express app with app.set('view engine', 'ejs'). Then, render .ejs files from the views directory using res.render(), as EJS complies with the Express view system.

EJS vs Handlebars: which should I choose?

EJS uses raw JavaScript for logic, offering flexibility but risking messy code, while Handlebars has a logic-less syntax that enforces cleaner separation. Pick EJS for JavaScript familiarity in simple projects, Handlebars for more structured templating.

How to include partials or reusable components in EJS?

Use the syntax with the raw output tag to avoid double-escaping. Ensure the filename option is set or use renderFile(), and pass local variables as needed, as explained in the includes section.

Is EJS safe for rendering user-generated content?

Not by default—EJS can execute JavaScript, so you must escape inputs using for safe output or sanitize data beforehand. The README cautions against giving end-users unfettered access to the render method to prevent code injection.

Can I run EJS templates directly in the browser?

Yes, download ejs.js or ejs.min.js from the latest release, include it in your HTML, and use ejs.render() with template strings and data objects. However, includes and filesystem methods like renderFile() won't work without callbacks.

How to cache templates in EJS for better performance?

Enable caching by setting the cache option to true when compiling templates. For advanced control, use an LRU cache by assigning ejs.cache to an instance of lru-cache, as shown in the caching example to limit stored functions.

EJS — Simple JavaScript Templating Language

What is EJS?

EJS is a templating engine for JavaScript that allows developers to generate HTML markup by embedding JavaScript code directly within templates. It solves the problem of creating dynamic web pages by providing a simple syntax to mix logic and presentation, making it easy to render data-driven content on both the server and client side.

Target Audience

JavaScript developers building web applications with Node.js or needing client-side templating, particularly those using Express.js who want a straightforward, JavaScript-based template engine.

Value Proposition

Developers choose EJS for its simplicity and familiarity—it uses plain JavaScript syntax within templates, requires minimal learning curve, and integrates seamlessly with Express.js, offering a lightweight yet powerful alternative to more complex templating languages.

Embedded JavaScript templates -- http://ejs.co

Use Cases

Best For

Generating dynamic HTML on the server with Node.js
Building Express.js applications that require server-side rendering
Creating reusable template components with includes
Quick prototyping of web pages with embedded JavaScript logic
Client-side rendering of templates in the browser
Projects needing a simple, non-opinionated templating solution

Not Ideal For

Projects requiring advanced template inheritance or block-based layouts without manual includes
Modern single-page applications that benefit from component-based frameworks like React or Vue
Security-sensitive applications with untrusted user input, due to EJS's ability to execute arbitrary JavaScript
Large-scale systems needing highly optimized templating with minimal runtime overhead

Pros & Cons

Pros

Familiar JavaScript Syntax

Uses standard JavaScript within <% %> tags, allowing developers to write logic without learning a new templating language, as highlighted in the philosophy of prioritizing developer familiarity.

Seamless Express Integration

Works as a drop-in view engine for Express.js, enabling easy server-side rendering in Node.js applications with minimal setup, as noted in the features section.

Client-Side Support

Can render templates in browsers using the same syntax, facilitating isomorphic applications, with examples provided for including ejs.js files and using ejs.render().

Customizable and Caching

Offers configurable delimiters and built-in caching options, including LRU cache integration, to improve performance and adapt to different coding environments, as detailed in the options and caching sections.

Cons

Security Risks with Inputs

The README explicitly warns that EJS can execute arbitrary JavaScript, making it inherently insecure if used with unchecked user data, such as in the vulnerable snippet res.render('index', req.query).

No Native Layout System

Lacks built-in support for template inheritance or blocks; implementing layouts requires manual includes of headers and footers, which can become cumbersome in complex projects, as admitted in the layouts section.

Potential for Messy Code

Mixing HTML and JavaScript directly in templates can lead to hard-to-maintain, spaghetti-like code, especially in views with extensive logic, contrasting with more declarative modern frameworks.

What is EJS?

Target Audience

JavaScript developers building web applications with Node.js or needing client-side templating, particularly those using Express.js who want a straightforward, JavaScript-based template engine.

Value Proposition

Use Cases

Best For

Generating dynamic HTML on the server with Node.js
Building Express.js applications that require server-side rendering
Creating reusable template components with includes
Quick prototyping of web pages with embedded JavaScript logic
Client-side rendering of templates in the browser
Projects needing a simple, non-opinionated templating solution

Not Ideal For

Projects requiring advanced template inheritance or block-based layouts without manual includes
Modern single-page applications that benefit from component-based frameworks like React or Vue
Security-sensitive applications with untrusted user input, due to EJS's ability to execute arbitrary JavaScript
Large-scale systems needing highly optimized templating with minimal runtime overhead

Pros & Cons

Pros

Familiar JavaScript Syntax

Uses standard JavaScript within <% %> tags, allowing developers to write logic without learning a new templating language, as highlighted in the philosophy of prioritizing developer familiarity.

Seamless Express Integration

Works as a drop-in view engine for Express.js, enabling easy server-side rendering in Node.js applications with minimal setup, as noted in the features section.

Client-Side Support

Can render templates in browsers using the same syntax, facilitating isomorphic applications, with examples provided for including ejs.js files and using ejs.render().

Customizable and Caching

Cons

Security Risks with Inputs

No Native Layout System

Potential for Messy Code

Mixing HTML and JavaScript directly in templates can lead to hard-to-maintain, spaghetti-like code, especially in views with extensive logic, contrasting with more declarative modern frameworks.

EJS

What is EJS?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?

EJS

What is EJS?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?