When should I use URL encoding?

URL encoding should be used whenever you need to include special characters in a URL, such as spaces, ampersands, question marks, or non-ASCII characters. Web browsers and servers expect URLs to contain only valid ASCII characters, so special characters must be converted to their %XX hexadecimal representation.

What is Base64 encoding used for?

Base64 encoding is used to convert binary data into ASCII text format. Common uses include embedding images directly in HTML or CSS, transmitting binary data through text-only protocols like email (MIME), encoding authentication credentials in HTTP headers, and storing binary data in JSON or XML documents.

What are HTML entities and why are they needed?

HTML entities are special codes that represent characters which have reserved meaning in HTML, such as (greater than), & (ampersand), and " (double quote). Using entities prevents the browser from interpreting these characters as HTML markup, which could break your page layout or create security vulnerabilities like XSS attacks.

How does Unicode escape sequence encoding work?

Unicode escape sequences represent non-ASCII characters using the \uXXXX format, where XXXX is the four-digit hexadecimal Unicode code point. This is commonly used in JavaScript, JSON, and other programming contexts where source files are restricted to ASCII characters but need to represent international text.

Is the encoding performed locally or sent to a server?

All encoding and decoding operations are performed entirely within your browser using JavaScript. No data is transmitted to any external server, ensuring complete privacy and security for your sensitive text content. This also means the tool works offline once the page is loaded.

Encoder Decoder - URL Base64 HTML Unicode Converter | Free Online

Converts special characters that cannot be used in URLs to %XX format.

Original Text

Encoded Text

Examples

URL Encoding

Hello World

↓

Hello%20World

Base64

Hello

↓

SGVsbG8=

HTML Entity

<div>

↓

<div>

Unicode

안녕

↓

\uc548\ub155

What is Encoder/Decoder?

Encoder/Decoder is a versatile online tool that converts text between various encoding formats including URL encoding, Base64, HTML entities, and Unicode escape sequences. Encoding transforms data into a safe, transmittable format, while decoding reverses the process back to human-readable text. This tool is essential for web developers, API engineers, and anyone who needs to handle encoded data in URLs, HTML documents, email systems, or data transmission protocols.

URL encoding and decoding for safe transmission of special characters in web addresses
Base64 encoding and decoding for binary-to-text data conversion
HTML entity conversion to safely embed special characters in HTML documents
Unicode escape sequence conversion for non-ASCII character handling
Bidirectional real-time conversion with instant results as you type
One-click copy functionality for quick integration into your workflow

How to Use

1
Select Encoding Type
Choose the encoding format you need from the available tabs: URL, Base64, HTML Entity, or Unicode. Each tab provides bidirectional conversion between the original and encoded forms.
2
Enter Your Text
Type or paste your text into either the 'Original Text' field (to encode) or the 'Encoded Text' field (to decode). The conversion happens automatically in real time.
3
Review the Result
The converted text appears instantly in the opposite field. Verify that the encoding or decoding matches your expectations before copying.
4
Copy the Output
Click the copy button next to the result to copy it to your clipboard. You can then paste the encoded or decoded text wherever you need it.

Frequently Asked Questions

Tips & Best Practices

Always URL-encode query parameter values in API requests to prevent parsing errors and potential security issues.
When working with Base64, remember that encoded output is approximately 33% larger than the original data due to the encoding scheme.
Use HTML entity encoding for all user-generated content displayed on web pages to prevent cross-site scripting (XSS) vulnerabilities.
Double-check decoded output for correctness — if the result looks garbled, the input may have been encoded with a different character set or method.
For Base64-encoded images, the format typically starts with 'data:image/png;base64,' followed by the encoded data string.