Base64 / URL / HTML Entities

Encode and decode Base64, URL encoding, and HTML entities. All-in-one encoding tool for web development.

Format Information

Base64: A binary-to-text encoding scheme that represents binary data in ASCII format using 64 characters (A-Z, a-z, 0-9, +, /).

Common Uses: Email attachments, data URLs, storing binary data in JSON/XML, API authentication tokens.

Note: Base64 encoding increases data size by approximately 33%.

What It Does

A Base64 / URL / HTML Entities Encoder is a multi-format encoding tool that combines three essential encoding methods in one powerful interface. It supports Base64 encoding (binary-to-text encoding for data transmission), URL encoding (percent-encoding for safe URL transmission), and HTML entity encoding (escaping special characters for HTML). This all-in-one tool allows developers to switch between formats seamlessly, encode or decode text instantly, and handle various encoding needs without switching between different tools. Perfect for web development, API work, data transmission, escaping special characters, and ensuring safe text handling across different contexts. All encoding and decoding happens client-side in your browser, ensuring privacy and security.

Key Features:

  • Three encoding formats in one tool: Base64, URL encoding, and HTML entities
  • Tabbed interface for easy switching between formats
  • Bidirectional encoding: encode text or decode encoded strings
  • Real-time conversion with instant results
  • Copy-to-clipboard functionality for quick use
  • Format information and examples for each encoding type
  • Client-side processing - all encoding happens in your browser
  • Support for large text inputs and outputs

How To Use

Using the multi-format encoder is straightforward. Choose your format, enter text, and encode or decode instantly.

1

Choose Your Format

Select the encoding format you need: Base64 (for binary data, email attachments, data URLs), URL encoding (for query parameters, form data), or HTML entities (for escaping special characters in HTML).

2

Enter Text to Encode or Decode

Enter the text you want to encode in the input field, or paste an already-encoded string (Base64, URL-encoded, or HTML entities) to decode it back to plain text.

3

Click Encode or Decode

Click the "Encode" button to convert your text to the selected format, or click "Decode" to convert encoded text back to plain text. The result appears instantly in the output field.

4

Switch Between Formats

Use the format tabs to switch between Base64, URL encoding, and HTML entities. You can see how the same text looks in different encoding formats by switching tabs.

5

Copy and Use

Click the "Copy" button to copy the encoded or decoded result to your clipboard. Use the encoded text in your code, URLs, HTML, or API requests as needed.

Pro Tips

  • •Base64 increases data size by ~33% - use for small to medium data
  • •URL encoding is essential for query parameters and form submissions
  • •HTML entities prevent XSS attacks by escaping special characters
  • •Switch between formats to see how the same text encodes differently
  • •Use Base64 for embedding binary data in JSON or XML
  • •URL encoding is required for special characters in URLs (spaces, &, =, etc.)
  • •HTML entities are needed for displaying <, >, &, ", ' in HTML safely

Benefits

All-in-One Tool: Three encoding formats in one interface, no need to switch tools
Web Development: Essential for API work, form handling, and data transmission
Security: Properly escape special characters to prevent XSS and injection attacks
Data Transmission: Encode data for safe transmission in URLs, JSON, or HTML
Time Saving: Quick encoding/decoding without looking up encoding rules
Privacy: All processing happens client-side in your browser
Format Flexibility: Switch between formats to see different encodings
Developer Friendly: Clear format information and examples for each encoding type

Use Cases

API Development

Encode data for API requests, especially for authentication tokens, query parameters, or JSON payloads. Base64 is common for tokens, URL encoding for query strings.

Encode API key "my-api-key-123" to Base64 for authentication header: bXktYXBpLWtleS0xMjM=

Form Data Submission

URL encode form data before submission to ensure special characters are properly transmitted. Essential for form fields containing spaces, ampersands, or other special characters.

URL encode form value "John & Jane" to "John%20%26%20Jane" for safe form submission

HTML Content Security

Encode user input as HTML entities to prevent XSS attacks and ensure special characters display correctly in HTML.

Encode user comment "<script>alert('xss')</script>" to HTML entities to prevent script execution

Data URLs and Embedding

Use Base64 encoding to embed images or data directly in HTML/CSS as data URLs, eliminating external file requests.

Convert small image to Base64 data URL: data:image/png;base64,iVBORw0KGgo...

URL Query Parameters

URL encode query parameters to ensure special characters don't break URLs or cause parsing errors.

Encode search query "c++ programming" to "c%2B%2B%20programming" for URL query parameter

Email and Data Transmission

Use Base64 encoding for email attachments, binary data in JSON, or any scenario requiring ASCII-safe binary representation.

Encode binary file data to Base64 for inclusion in JSON API response

Frequently Asked Questions

1 What is the difference between Base64, URL encoding, and HTML entities?
Base64 converts binary data to ASCII text using 64 characters (A-Z, a-z, 0-9, +, /). It's used for embedding binary data in text formats. URL encoding (percent-encoding) converts special characters to %XX format for safe URL transmission (e.g., space becomes %20). HTML entities escape special HTML characters using &name; or &#number; format (e.g., < becomes &lt;). Each serves different purposes: Base64 for binary data, URL encoding for URLs, HTML entities for HTML content.
2 When should I use Base64 encoding?
Use Base64 for: embedding images or files in data URLs, storing binary data in JSON/XML, email attachments (MIME), API authentication tokens, or any scenario where binary data needs to be represented as ASCII text. Note that Base64 increases data size by approximately 33%, so it's best for small to medium data. For large files, consider other methods.
3 When should I use URL encoding?
Use URL encoding for: query parameters in URLs, form data submission (application/x-www-form-urlencoded), URL path segments with special characters, or any text that will be part of a URL. Special characters like spaces, &, =, ?, # must be URL-encoded to prevent breaking URL structure. Modern browsers handle this automatically for URLs, but you may need manual encoding for API requests or programmatic URL construction.
4 When should I use HTML entities?
Use HTML entities for: displaying special characters in HTML (<, >, &, ", '), preventing XSS attacks by escaping user input, ensuring special characters render correctly in HTML, or when you need literal characters that have meaning in HTML. Common entities: &lt; for <, &gt; for >, &amp; for &, &quot; for ", &#39; for '. Modern frameworks often handle this automatically, but manual encoding may be needed for certain scenarios.
5 Can I decode encoded text back to original?
Yes! All three encoding formats are reversible. Base64 can be decoded back to original binary/text data, URL encoding can be decoded back to original text, and HTML entities can be decoded back to original characters. The tool supports both encoding and decoding for all three formats. Simply paste the encoded string and click "Decode" to get the original text.
6 Is my data kept private during encoding?
Yes! All encoding and decoding happens entirely in your browser using JavaScript. Your text is never uploaded to any server, transmitted over the internet, or stored anywhere. This ensures complete privacy and security, which is especially important when encoding sensitive data like API keys, tokens, or user information.

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