HTML Entity Encoder & Decoder
Encode and decode HTML entities, special characters, and numeric code points client-side
About HTML Entity Encoder & Decoder
How HTML Entity Encoder & Decoder Works
Scans strings for markup delimiters and special Unicode symbols, replacing them with standard W3C named character entities (<, >, &), decimal codes (<), or hex numeric character references (<) client-side in browser memory with zero network overhead.
HTML Entity Encoder & Decoder is an essential client-side security and web development utility for escaping raw markup and safely embedding dynamic user text into HTML, XML, SVG, and web applications. It transforms reserved markup delimiters (&, <, >, ", ') and non-ASCII characters into named character references (like &, <, >), decimal character codes (<), or hexadecimal numeric character references (<) to protect against Cross-Site Scripting (XSS) and markup injection. In decoder mode, it accurately resolves both named entities and arbitrary numeric code points back into human-readable plaintext without making network calls or running untrusted scripts.
Frequently asked questions
Why is HTML entity encoding important for web security?+
When user-supplied text contains raw '<' or '>' characters and is rendered directly into HTML without escaping, browsers interpret the text as executable markup or script tags, leading to Cross-Site Scripting (XSS). Replacing these characters with entities ensures the browser treats them strictly as visual text rather than executable markup.
What is the difference between Named, Decimal, and Hex entities?+
Named entities use human-friendly abbreviations defined by W3C HTML specifications (such as © or <). Decimal entities use the decimal Unicode code point (© or <). Hexadecimal entities use the hex notation (© or <). All three render identically in modern browsers, with hex and decimal offering universal compatibility for any Unicode character.
What characters are encoded in 'Basic HTML (XSS)' mode?+
Basic HTML mode targets the five essential characters that break markup context: ampersand (&), less-than (<), greater-than (>), double quotation mark ("), and single quotation mark / apostrophe (').
Does this tool execute or evaluate the HTML code?+
No. The encoder and decoder execute pure lexical string transformations using regular expressions. It never invokes eval(), document.write(), or innerHTML, ensuring 100% safety even when handling malicious exploit payloads.
Is any encoded or decoded text uploaded to a server?+
No. All transformations run entirely inside your browser's local JavaScript engine. Your private code snippets, database records, and customer payloads never leave your computer.
Limitations
HTML entity encoding sanitizes character representations for standard HTML text contexts, but it does not replace context-aware escaping required inside inline JavaScript blocks or unquoted HTML attributes.