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Encode special characters to HTML entities (like & → &, < → <, © → ©) with named entity preference, numeric entity options, and safe HTML display for preventing XSS vulnerabilities and preserving markup structure.
Note: AI can make mistakes, so please double-check it.
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Common questions about this tool
Paste your text containing special characters into the HTML entity encoder. It converts characters like <, >, &, and quotes to their HTML entity equivalents (<, >, &) to make text safe for HTML display.
Characters that have special meaning in HTML should be encoded: < (<), > (>), & (&), quotes (" or '), and copyright symbols (©). Encoding prevents these from being interpreted as HTML markup.
The encoder uses named entities (like &) by default for readability. Some tools allow numeric entities (&) as an option. Named entities are more readable, while numeric entities work in all HTML contexts.
Use the HTML entity decoder tool to convert HTML entities back to their original characters. This is useful when extracting text from HTML or processing encoded content.
HTML entity encoding prevents XSS (cross-site scripting) attacks by ensuring user input is displayed as text rather than executed as HTML. It's essential for safely displaying user-generated content on web pages.
Verified content & sources
This tool's content and its supporting explanations have been created and reviewed by subject-matter experts. Calculations and logic are based on established research sources.
Scope: interactive tool, explanatory content, and related articles.
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Learn what this tool does, when to use it, and how it fits into your workflow.
The HTML Entity Encoder converts raw text into HTML-safe entity sequences. It turns characters like <, >, &, quotes, and non-ASCII symbols into HTML entities so that they display correctly inside web pages without breaking the layout or opening security holes.
When you show user input, code samples, or any untrusted content in HTML, you must encode it first. If you do not, the browser may treat it as real HTML or script. This can result in layout bugs or serious security issues such as cross-site scripting.
This tool solves that problem by applying encoding rules that match the context where your text will appear. It supports different encoding modes for text content, attributes, code blocks, and UTF-8 friendly output. You can also choose between named entities, decimal entities, and hexadecimal entities.
The HTML Entity Encoder is aimed at web developers, security engineers, template authors, and technical writers who need a reliable way to turn raw strings into safe HTML output. It is suitable for both beginners who want guidance and advanced users who care about fine details in encoding behavior.
HTML is a markup language that uses special characters to define structure. The characters < and > mark the start and end of tags. The character & introduces entities. Quotes define attribute values. Because of this, they cannot appear directly inside HTML in every context without extra care.
To solve this, HTML uses entities. An entity is a short code that starts with & and ends with ;. Inside, there may be a name, such as <, or a number such as < or <. The browser replaces entities with their matching characters after it parses the page. A related operation involves encoding HTML entities as part of a similar workflow.
Entity encoding is essential for two main reasons. First, it keeps your layout safe. When you encode special characters, the browser does not confuse them with real tags or attributes. Second, it protects against script injection. Untrusted text that contains angle brackets, quotes, or ampersands can become active script or markup if you do not encode it correctly.
However, manual encoding is hard. You must remember which characters are dangerous in a given context. For example, the rules for text inside a paragraph differ from the rules for values inside attributes. You also need to decide whether to use named entities, decimal entities, or hex entities. Different teams and content pipelines prefer different styles.
The HTML Entity Encoder in this project formalizes these rules. It uses defined encoding modes that map to common HTML contexts and a clear strategy for naming or numbering entities. The logic is based on actual character properties such as ASCII codes and whether a character is alphanumeric, a space, or something else.
Safely displaying user comments: When you need to place raw user text into a web page, use TEXT or UTF8_FRIENDLY mode to encode dangerous characters. This prevents comments from injecting tags or script.
Encoding values for HTML attributes: When you want to place user content inside attributes such as title, alt, or data-*, use ATTRIBUTE mode. It encodes nearly everything except letters and digits, reducing breakout risk. For adjacent tasks, html encoder operations addresses a complementary step.
Creating code examples for documentation: When writing docs or tutorials that show HTML or script snippets, use CODE mode. It makes sure that your example markup appears as text in the browser rather than being executed.
Normalizing entity style in content pipelines: If your team prefers numeric entities, you can choose DECIMAL or HEX format. The encoder will convert every character that needs encoding into that style, giving you consistent, machine-friendly output.
Checking external content for unsafe characters: Paste text from third-party sources and see how the encoder transforms it. Combined with AI insights, this helps you decide whether you need stricter rules at import time.
Decoding legacy HTML-encoded strings: Toggle to decode mode and paste strings that already contain entities. The tool shows the decoded result, which is useful when you need to inspect or migrate old data.
& and <.The core encoding function accepts the input string, an encoding mode, and an entity format. It first checks for an empty input and returns an empty string in that case. When working with related formats, decoding HTML characters can be a useful part of the process.
For non-empty input, it splits the string into characters. For each character, it records the character code via charCodeAt(0) and checks whether the character is one of the basic HTML syntax characters: ampersand, less-than, greater-than, double quote, or single quote.
The function then applies mode-specific rules. In UTF8_FRIENDLY mode, if the character is not one of the basic syntax characters, it is left as-is. In TEXT mode, the function encodes the basic syntax characters and all non-ASCII characters (code greater than 127), but keeps safe ASCII characters.
In ATTRIBUTE mode, the function uses a stricter rule. It leaves only alphanumeric characters (letters and digits) unchanged. All other characters, including spaces and punctuation, are marked for encoding. In CODE mode, it is even stricter: it leaves only spaces and alphanumeric characters, encoding everything else.
After mode rules, the function decides the entity format. If the format is NAMED and the character is in the basic mapping, it returns the named entity from the map, such as & or <. If the format is HEX, it builds a hex entity from the character code using code.toString(16).toUpperCase() inside a &#x...; wrapper.
If neither of these conditions hold, the function falls back to decimal entities. It wraps the code in &#...;. After processing every character, it joins the results into one string and returns it. In some workflows, encoding URL components is a relevant follow-up operation.
The decode function takes a different path. It uses DOMParser to parse the input string as HTML and then reads documentElement.textContent. This performs standard browser entity decoding. If the decoded result is the same as the input but the input still contains ampersands, it runs a manual series of replacements for common named and numeric patterns. This hybrid approach handles many real-world cases while staying simple.
| Mode | Allowed characters | Typical context |
|---|---|---|
| TEXT | ASCII letters, digits, some punctuation | Paragraph text, basic content nodes |
| ATTRIBUTE | Letters and digits only | Attribute values in tags |
| CODE | Letters, digits, spaces | Code samples in <pre> or <code> blocks |
| UTF8_FRIENDLY | All except basic syntax characters | Localized content that should remain readable |
Pick the right mode for the context: Use ATTRIBUTE mode for attributes, CODE mode for samples, and TEXT or UTF8_FRIENDLY for general content. This keeps encoding strict where it must be and relaxed where it can be.
Prefer named entities for clarity: Named entities such as & and < are easier to read and remember. Use them when working directly with templates or documentation.
Use numeric entities for full coverage: For characters that do not have standard names, or when you want an unambiguous representation, choose DECIMAL or HEX format. This is helpful in pipelines and automated tools.
Do not encode more than once: Double-encoding leads to sequences like &amp;. If you suspect this, decode once with the same tool, then re-encode with the correct mode. For related processing needs, url encoder operations handles a complementary task.
Respect the input size limit: Very large strings may be slow to process in the browser. Keep input within the 500 KB limit, and consider splitting huge texts into smaller parts.
Review AI recommendations carefully: The AI insights can suggest safer patterns and highlight risks, but they are based on analysis of your text, not your full system. Treat them as guidance, not as rules.
Keep original raw data: Store original user input or source content before encoding. This lets you change encoding rules later without losing meaning.
Test in real browsers: After encoding, render your content in a target browser to confirm that it appears and behaves as expected, especially for complex Unicode characters or mixed scripts.
Avoid mixing encoding layers: If another library also encodes entities, you may see unexpected results. Decide which part of your pipeline is responsible for HTML entity encoding and stick to it.
Use decode mode for debugging: When you encounter strange sequences in HTML or logs, switch to decode mode to understand what users actually see. This helps diagnose upstream encoding problems.
Articles and guides to get more from this tool
1. What This Topic Is An HTML Entity Encoder is a method for converting certain characters into their HTML entity representations so…
Read full articleSummary: Encode special characters to HTML entities (like & → &, < → <, © → ©) with named entity preference, numeric entity options, and safe HTML display for preventing XSS vulnerabilities and preserving markup structure.