Encode and decode Base64 strings instantly. Support for text and binary data. Free online developer tool. This tool runs entirely in your browser — no data is sent to any server. It's fast, free, and works on any device.
Base64 is a binary-to-text encoding scheme that represents binary data using a set of 64 ASCII characters (A–Z, a–z, 0–9, +, /). It was designed to safely transmit binary data over systems that were built to handle text — like email (MIME) or embedding images in HTML/CSS. A Base64-encoded string is about 33% larger than the original binary, but it can pass through any text-based protocol without corruption. Common uses include embedding images as data URIs in CSS, encoding JWT tokens, transmitting binary data in JSON, storing small files in databases, and Basic Authentication headers. This tool handles encoding and decoding instantly in your browser.
Base64 works in 3-byte groups, producing 4 characters. If input length isn't divisible by 3, the output is padded with = characters to complete the last group. It's just alignment, not data.
No! Base64 is encoding, not encryption. Anyone can decode a Base64 string instantly. Never use it to hide sensitive data. Use proper encryption (AES, RSA) for security.
Standard Base64 uses + and / which are special characters in URLs. URL-safe Base64 replaces them with - and _, making the output safe for use in URLs and filenames.
Yes! Use our Image to Base64 tool for converting image files to Base64 data URIs that can be embedded directly in HTML or CSS.
Every 3 bytes of binary become 4 Base64 characters (a 33% increase). This overhead is the trade-off for guaranteed text-safe transmission across systems that might corrupt binary data.