Encoding and decoding are fundamental operations in software development. Every time data crosses a boundary — from browser to server, from one system to another, from binary to text — encoding ensures that data arrives intact and is interpreted correctly.
**Base64 encoding** converts binary data into a safe ASCII text representation using a 64-character alphabet (A-Z, a-z, 0-9, +, /). Developers encounter Base64 constantly: embedding images as data URIs in CSS or HTML, transmitting binary data in JSON payloads, encoding email attachments via MIME, and working with JWT tokens that use Base64URL encoding. Our Base64 tool handles encoding and decoding with full Unicode support, and can even convert images to Base64 data URIs.
**URL encoding** (also called percent-encoding) replaces characters that have special meaning in URLs with percent-encoded equivalents. For example, a space becomes %20, an ampersand becomes %26. This is essential when building query strings, constructing API URLs with dynamic parameters, or handling user input that will appear in URLs. Our URL encoder provides both full URL encoding and component encoding, plus a URL parser that breaks any URL into its constituent parts.
Understanding when to use which encoding is a skill every developer needs. Base64 is for embedding binary data in text contexts. URL encoding is for making strings safe for use in URLs. HTML encoding is for displaying user content safely in web pages. Each serves a specific purpose, and using the wrong one leads to bugs, security vulnerabilities, or corrupted data.
All encoding tools on this site process data entirely in your browser. This is particularly important for encoding operations, which often involve sensitive data like API tokens, authentication headers, or user credentials. Your data never leaves your machine.
These tools handle edge cases that catch developers off guard: Unicode characters in Base64 (which standard btoa() cannot handle), the difference between encodeURI and encodeURIComponent, and proper handling of plus signs in query strings versus path segments.