HTML Encoding (or HTML Escape Encoding) is the process of converting special characters in text or data into their corresponding HTML entities. HTML encoding is crucial when embedding data into HTML documents because certain characters have special meanings in HTML, such as <, >, &, and ". Encoding these characters ensures they are displayed properly and not interpreted as HTML code.
Why HTML Encoding?
HTML encoding is necessary to:
Prevent HTML Injection: Special characters such as <, >, and & are reserved in HTML. Encoding them prevents these characters from being treated as HTML tags or entities and ensures they are displayed as plain text.
Display Special Characters: Some characters like ©, ®, or even (space) might need to be represented by their respective HTML codes to ensure consistent rendering in browsers.
Ensure Correct Rendering: Encoding ensures that characters with special meanings in HTML (e.g., <, >, &, ") are displayed correctly and not misinterpreted as HTML elements or attributes.
Common HTML Entities:
Here are some of the most common characters and their corresponding HTML encoded forms:
Character HTML Entity
& &
< <
> >
" "
' ' or ‘ (depending on usage)
© ©
® ®
€ €
™ ™
(space)  
HTML Encoding Process:
HTML encoding involves replacing characters with their corresponding HTML entities. Here's how it works:
Characters like <, >, and & are replaced with their HTML entities (<, >, &).
Other characters, such as " and ', may also be encoded to avoid conflicts with HTML attributes.
Non-ASCII characters (such as ©, é) may be replaced with their respective HTML entities or Unicode representations.
HTML Encoding Example:
Let's say we want to encode the following string:
Original text: Hello <World> & "Everyone" 'Here'
HTML Encoded version: Hello <World> & "Everyone" 'Here'
How to Encode HTML:
You can encode HTML manually by replacing special characters with their corresponding entities, or you can use various programming functions to automatically perform the encoding.
Popular Methods in Programming Languages:
JavaScript: Use encodeURIComponent() or document.createTextNode().
Python: Use html.escape().
PHP: Use htmlspecialchars().
Java: Use StringEscapeUtils.escapeHtml4() from the Apache Commons Lang library.