innerHTML has been around since the early days of the web.
It’s used in millions of websites to manipulate the DOM efficiently.

✅ Advantages of innerHTML:-

1. Simplicity and Convenience : It is very easy to use and perfect for quickly injecting or replacing a block of HTML.

2. Performance : Updating large chunks of HTML in one go is often faster than building DOM nodes individually. Especially useful for rendering static templates or HTML responses from the server.

3. Supports Complete HTML Features : Capable of rendering: nested elements , inline styles , SVGs etc.

⛔️ When innerHTML Becomes Dangerous ?

1. Security Risk (XSS) : It can easily lead to Cross-Site Scripting (XSS) vulnerabilities if used with user-controlled data. It can easily be exploited to inject malicious scripts if you're inserting untrusted content.

Example :-

const userInput = document.getElementById('comment-box').value;
element.innerHTML = userInput;  // If userInput contains <script>alert('XSS')</script>, it will execute.

2. DOM Rebuild Overhead : Using innerHTML repeatedly (like in a timer, clock, or live feed) forces the browser to:

• Remove all existing child elements
• Parse the new HTML string
• Rebuild and insert everything again

This constant process is inefficient for real-time updates. It leads to unnecessary reflows and repaints, which can affect performance.

🔒 Recommendation:

✅ Use innerHTML only when you control 100% of the content being inserted.

✅ If the content comes from a user (like a form or a comment), use textContent to show it as plain text, or sanitize it with a tool like DOMPurify before adding it to the page.

// Safer option:
const safeHTML = DOMPurify.sanitize(userInput);
element.innerHTML = safeHTML;

𐄷 Verdict:-

innerHTML is safe when the content is completely trusted — i.e., not user controlled. It remains a useful part of the web platform due to its simplicity, performance benefits, and legacy support.

As developers, it’s our responsibility to use it wisely. We should avoid it entirely when working with untrusted or dynamic input, to prevent serious vulnerabilities like Cross-Site Scripting (XSS).

Let me know what you think about this.