HTML <br> vs <br />: Differences, Best Practices & JSX Rules

If you have ever stared at your code editor wondering why Prettier keeps adding a slash to your break tags, or why your React console is throwing syntax errors over a simple line break, you are not alone. While the browser output looks identical for both, the distinction between <br> and <br /> is more than just a stylistic choice, it is about the standard you are building on.

In modern web development, understanding this difference ensures your code remains consistent, valid, and compatible with strict parsers like JSX.

The Short Answer: Does It Matter?

For a standard HTML5 document rendered in a browser, the short answer is no. Modern browsers are incredibly forgiving. Whether you write <br> (the HTML style) or <br /> (the XHTML/XML style), Chrome or Firefox will interpret it exactly the same way: as a line break.

However, context is everything. While HTML5 is permissible, modern tech stacks are not. If you are working in a JavaScript-heavy environment or aiming for code consistency across a large team, the trailing slash becomes mandatory rather than optional.

Understanding Void Elements

To understand why this confusion exists, we need to look at void elements. In HTML, a void element is a tag that cannot contain any child nodes (text or other tags). Since they have no content to enclose, they do not require a closing tag.

Common void elements include:

• <br> (Line Break)
• <img> (Image)
• <input> (Input Field)
• <hr> (Horizontal Rule)

In the classic HTML4 syntax, these were written simply as open tags. The concept of self-closing <br /> was introduced with XHTML, which applied stricter XML rules requiring all tags to be closed. Today, HTML5 supports both syntaxes, but void elements technically do not need to be closed.

The Critical Difference: HTML5 vs. JSX (React)

This is where most modern developers hit a wall. While HTML5 is lenient, JSX is not HTML. JSX (JavaScript XML) is a syntax extension used by React, and it strictly follows XML rules.

In XML, every tag must be closed. If you try to use a naked <br> in a React component, your compilation will fail with a syntax error.

Incorrect in JSX:

// ❌ This will throw an error: "Unterminated JSX contents"
return (
  <div>
    Hello World<br>
    Welcome to my site
  </div>
);

Correct in JSX:

// ✅ This compiles perfectly
return (
  <div>
    Hello World<br />
    Welcome to my site
  </div>
);

If you are transitioning from static HTML to a modern framework, adopting the self-closing <br /> habit early on saves you from refactoring headaches later. Understanding how rendering works in frameworks is key; for instance, knowing why state updates with objects don't rerender in React is just as important as knowing valid syntax.

Best Practices: When NOT to Use Line Breaks

One of the biggest mistakes beginners make is using the <br /> tag for layout purposes. If you find yourself writing <br /><br /><br /> to create space between elements, you are fighting against the Semantic Web.

The <br /> tag has a very specific semantic purpose: breaking lines of text (like in a poem or a postal address). It should never be used to create gaps between visual components.

Instead of line breaks, use CSS:

• Margins and Padding: Use standard CSS properties to control spacing.
• Modern Units: Utilize responsive units for better layouts. Using the right units, such as CSS vh, dvh, lvh, svh, and vw units, ensures your spacing adapts fluidly to mobile screens, whereas a hard-coded break does not.

Using CSS ensures that your visual structure is separated from your content structure, which is vital for accessibility (screen readers) and maintenance.

Automating Consistency with Prettier

In a professional environment, you should rarely have to make this decision manually. Code formatters like Prettier are the standard for maintaining consistency.

Most default Prettier configurations will automatically convert <br> to <br /> in HTML files to maintain a uniform self-closing style across the project, aligning your HTML code with your JSX/TSX codebases.

Recommendation: Configure your editor to auto-format on save. This removes the mental load of deciding which syntax to use and prevents nitpick comments during code reviews.

In summary, while the browser doesn't care, your tools and frameworks do. Use <br> if you are writing quick, raw HTML5. Use <br /> if you are working with React, XML parsers, or if you simply prefer the visual consistency of self-closing tags.