HTML Entity Encoder & Decoder: The Developer's Complete Reference
What is an HTML Entity? An HTML entity is a special text sequence used to represent characters that would otherwise be interpreted as HTML markup or are difficult to type directly. This tool lets you encode any text to HTML entities - in named (&), decimal (&), or hexadecimal (&) format - or decode entities back to readable text. The built-in symbol cheat sheet lets developers instantly copy arrows, currency signs, math operators, and Greek letters without memorizing a single entity name.
What Is the HTML Entity Encoder / Decoder?
This tool is a bidirectional converter for HTML character entities. Whether you are sanitizing user input before inserting it into a web page, debugging encoded content from an API, or looking up the entity code for the euro sign, this tool handles it instantly - entirely in your browser with no data sent to any server.
It supports all three entity formats defined by the HTML and XML specifications:
- Named entities: Human-readable shorthand, e.g.
©→ © - Decimal numeric references: Unicode code point in base-10, e.g.
©→ © - Hexadecimal numeric references: Unicode code point in base-16, e.g.
©→ ©
Why Use an HTML Entity Converter?
1. Prevent XSS and Broken Markup
The single most important use of HTML entity encoding is security. When you insert user-provided content into an HTML page without encoding it, a string like <script>alert(1)</script> gets executed by the browser. Encoding the HTML Critical characters (&, <, >, ", ') neutralizes the input, making it safe to display. Use the HTML Critical scope for this purpose.
2. Ensure Compatibility in Emails and Plain-ASCII Environments
Some email clients, legacy XML systems, and RSS feed parsers struggle with raw Unicode. Encoding special characters as numeric entities (e.g., € for €) guarantees the character is transmitted correctly even through systems that strip or mangle multi-byte UTF-8 sequences.
3. Look Up Entity Codes Instantly
The Symbol Library below the converter turns this tool into a developer cheat sheet. No more searching MDN for "HTML arrow entity" or "copyright symbol HTML code" - they are all one click away, categorized by type and ready to copy.
How to Use This Tool
- Choose Mode: Select Encode to convert characters into entities, or Decode to convert entities back into characters.
- Select Scope (Encode only):
- HTML critical - only
&,<,>,",', and - All named - every character that has a named HTML entity
- All non-ASCII - every character above U+007F
- HTML critical - only
- Choose Format (Encode only): Named (
&), Decimal (&), or Hex (&). - Paste or type your text into the left area. Output updates live.
- Browse the Symbol Library to find and copy entity codes for any symbol.
- Copy or Download the result using the buttons on the output panel.
Common Professional Use Cases
Frontend & Template Developers
Safely insert dynamic content into HTML attributes and text nodes without introducing XSS vectors.
Email Marketers
Encode currency symbols, arrows, and special characters in HTML email templates to maximize inbox rendering compatibility.
Content Editors & Copywriters
Quickly look up the entity code for em dashes, curly quotes, and trademark symbols when writing directly in HTML.
API & Data Engineers
Decode HTML-encoded strings returned by web scraping, CMS APIs, or legacy data exports to get clean, readable text.
Localization Teams
Encode non-ASCII characters in translation strings destined for systems that require pure ASCII with numeric entity fallbacks.
Security Researchers
Verify encoding output during manual code review to confirm that XSS mitigations are applied correctly on all user inputs.
Frequently Asked Questions (FAQs)
What is the difference between named and numeric HTML entities?
Named entities use a human-readable name like &, ©, or €. Numeric entities reference the Unicode code point, either as a decimal (&) or hexadecimal (&) number. All three render identically in browsers. Named entities require HTML5 or the correct DTD, while numeric entities work in any XML context including SVG and Atom feeds.
Does this tool support all HTML5 named entities?
The encoder/decoder covers all HTML 4 named entities (roughly 250 characters), which includes everything in common use. HTML5 adds over 2,000 additional named entities (mostly multi-character mathematical symbols); those less common ones fall back to numeric encoding automatically when using the All non-ASCII scope.
Which characters must always be encoded?
The five HTML Critical characters are mandatory when placing user input into HTML: & → &, < → <, > → >, " → ", and ' → '. Omitting even one of these when rendering untrusted content can lead to Cross-Site Scripting (XSS) vulnerabilities.
Should I use named entities or numeric entities in my HTML?
For HTML5 documents served with a UTF-8 charset, you can use raw Unicode characters or named entities - both work perfectly. Numeric entities are safer in XML contexts or when your authoring environment might corrupt multi-byte characters. For the five HTML Critical characters, named entities (&, <, etc.) are the conventional choice because they are instantly recognizable in source code.
Is my data private when using this tool?
Yes. All encoding and decoding happens directly in your browser using JavaScript. No text is ever sent to AllOverTools servers. You can use this tool confidently with sensitive source code, passwords, or proprietary content.
Conclusion
Whether you are hardening a web application against XSS attacks, preparing HTML email content for maximum compatibility, or simply hunting for the entity code of an em dash, the HTML Entity Encoder / Decoder is the tool you need. Combine it with the built-in symbol library, and you have a complete HTML character reference at your fingertips - free, private, and always available offline.