HTML Entity Reference

An HTML entity is a string that starts with & and ends with ; used to represent characters that are reserved in HTML or that cannot be typed directly. The most important are: &amp; for &, &lt; for <, &gt; for >, &quot; for ", and &apos; for '. Without these, a < in content would be interpreted as the start of a tag.

You must escape <, >, &, and " in HTML attributes and content. In a double-quoted attribute value: &amp;, &lt;, &gt;, &quot;. In element content: &amp;, &lt;, &gt;. If using single-quoted attributes: also &apos;. Modern frameworks like React handle this automatically — JSX escapes string content. Only use raw HTML (dangerouslySetInnerHTML) when you control the content entirely.

Named entities use a human-readable name: &copy; (©), &trade; (™), &euro; (€). Numeric entities use a decimal (&#169;) or hexadecimal (&#xA9;) Unicode code point. Named entities only exist for a subset of Unicode characters — for others, use numeric references. All three forms are equivalent: &copy; = &#169; = &#xA9; = ©.

No — HTML entities are HTML syntax. Inside a <script> tag or a JavaScript file, use JavaScript string escapes (\n, \t, \u00A9) rather than HTML entities. HTML entities are only relevant in HTML document context: attribute values, text nodes, and data- attributes accessed via innerHTML. Using &amp; inside JavaScript code is a common mistake that produces broken strings.

&nbsp; (&#160;) is the non-breaking space — a space character that prevents line breaks at that position and does not collapse with adjacent spaces. HTML collapses multiple whitespace characters into one, but &nbsp; is preserved. Use it for units (100&nbsp;km), between initials (J.&nbsp;Smith), or to force minimum spacing. Avoid overusing it for layout — use CSS instead.