What is Base64?

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, +, and /. It is commonly used to embed binary data in text-based formats like JSON, HTML, emails, and URLs.

How it works

The encoding process takes every 3 bytes (24 bits) of input and splits them into four 6-bit groups. Each group maps to one of the 64 characters. If the input length isn't a multiple of 3, the output is padded with = characters.

How to use this tool

• Type or paste plain text on the left — it is automatically encoded to Base64 on the right
• Type or paste a Base64 string on the right — it is automatically decoded to plain text on the left
• Toggle URL-safe mode to use - and _ instead of + and /, which is safer for URLs and filenames

Common use cases

• Embedding images in CSS or HTML as data: URIs
• Encoding credentials for Authorization: Basic HTTP headers
• Transferring binary data through JSON APIs or email (MIME)
• Storing binary blobs in text-only environments like environment variables or config files