HTML Encoder for Code Display

Encode HTML code for safe display in web pages by escaping angle brackets, quotes, and ampersands.

Tested tool guide Tested browser tools Checked August 16, 2026

What HTML Encoder for Code Display does, with a checked example

When a page needs to print HTML source instead of creating the elements it describes, this encoder changes syntax-significant characters into HTML character references. Ampersands, opening and closing angle brackets, and quotation marks are escaped so the result can be placed in ordinary HTML text content. The most common surprise is that a rendered page shows the original-looking tag. That is correct: the browser resolves the references into visible characters without interpreting those resolved brackets as a new element.

Worked example

A concrete input and expected output from the current implementation.

Input

<b>A & B</b>

Expected output

&lt;b&gt;A &amp; B&lt;/b&gt;

< and > are replaced with < and >, and the source ampersand is replaced with &. When parsed as HTML text, the result displays the literal text <b>A & B</b> instead of creating a bold element.

How the result is produced

Character replacement

For every matching input character, the result contains a character reference: & for &, < for <, and > for >. Quotation marks are encoded too, even though quotes do not delimit markup in an ordinary text node. After one HTML parse, these references produce the intended visible characters rather than tag or reference syntax.

Placement and rendering

The returned string is intended to be pasted into HTML source, often between <code> tags inside a <pre> element. Encoding controls parsing, not layout. <code> identifies a code fragment, while <pre> normally retains line breaks and runs of spaces. This encoder does not indent, validate, highlight, execute, or otherwise repair the supplied markup.

Good uses

Showing a literal <button type="button"> example in an HTML tutorial without producing a clickable button.
Embedding copied component markup in a documentation page's <pre><code> block while keeping every tag visible.
Turning a tag-shaped error payload such as <unexpected> into visible text for an HTML diagnostics panel.

Limits and checks

Treat the output as HTML-text-context escaping. It is not a universal encoding for JavaScript strings, CSS, URL components, JSON, or every attribute form; those contexts have different delimiters and parsing rules.
Do not encode an already encoded result unless double encoding is intended. For example, a second pass changes < to &lt;; one browser parse then displays <, not the less-than sign.
The output says nothing about whether the input is valid HTML. Unclosed elements, misspelled attributes, and impossible nesting are escaped as literal text. Rendered spaces may also collapse unless the surrounding element or CSS preserves them.

Common questions

Will the encoded output display as a formatted code block by itself?

No. The encoded string controls how HTML parsing treats the source characters; it does not supply code styling or whitespace preservation. Put it in <code> for code semantics, and use <pre> or suitable CSS when indentation and line breaks must remain visible. If the string is inserted through a text-only DOM operation instead of parsed as HTML, its < sequences can appear literally.

Is HTML encoding the same as sanitizing untrusted HTML?

No. Encoding the entire value is appropriate when every tag-shaped part must be displayed literally in ordinary HTML text. Sanitization instead permits selected markup and rejects or rewrites other content. This tool does not choose an allowlist or preserve safe tags. Attribute values, script data, style data, and URLs require context-specific handling rather than assuming this output is sufficient.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.