Base64 Encoder/Decoder

Base64 Encoder/Decoder is a free online tool that converts text to and from Base64 encoding. Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format, commonly used to embed data in URLs, emails, HTML, and API payloads where binary data cannot be transmitted directly.

The tool supports both standard Base64 encoding (RFC 4648) and URL-safe Base64 encoding, which replaces the + and / characters with - and _ to make the output safe for use in URLs and filenames. You can encode plain text to Base64 or decode Base64 strings back to readable text with a single click.

Whether you are a developer working with APIs that require Base64-encoded data, debugging encoded strings, or encoding configuration values, this tool provides instant conversion with clear input and output. All processing happens in your browser, keeping your data completely private.

Base64 is an encoding, not encryption, and the distinction matters because it is regularly mistaken for one. Anything encoded here can be decoded by anyone in a second, so it protects nothing: its job is to carry binary data through channels that only reliably survive text, such as email bodies, JSON strings and data URIs. The cost is size. Every three bytes become four characters, so the output is about 33 per cent larger than the input, which is why inlining a large image as a data URI can make a page slower rather than faster. The URL-safe variant swaps the two characters that have meaning in a URL, plus and slash, for minus and underscore, and is what JWTs use. Padding with equals signs is required by the standard but tolerated as optional by most decoders.