Base64 Encode/Decode
Encode text to Base64 or decode Base64 strings instantly. Supports UTF-8 text with auto-detection and one-click copy.
About Base64 Encode/Decode
The Base64 Encode/Decode tool lets you convert text to Base64 encoding and back with a single click. Base64 is one of the most widely used encoding schemes in web development, used everywhere from data URIs in CSS to authentication headers in HTTP requests.
This tool fully supports UTF-8 text, correctly handling multi-byte characters like accented letters, Chinese characters, emoji, and other Unicode content. The encoding process first converts your text to UTF-8 bytes, then applies standard Base64 encoding to produce a safe ASCII string.
The auto-detect mode intelligently determines whether your input is already Base64-encoded or is plain text that needs encoding. This saves you from having to manually choose the operation each time. You can also explicitly select encode or decode when you know exactly what you need.
Common use cases include encoding images or files for embedding in HTML or CSS data URIs, preparing data for inclusion in JSON payloads, working with HTTP Basic Authentication headers, debugging encoded values in API requests and responses, and handling email attachments in MIME format.
All encoding and decoding happens locally in your browser. No data is transmitted to any server, so you can safely work with API keys, tokens, and other sensitive strings without concern. The output area includes a one-click copy button for easy transfer to your code editor or terminal.
Frequently Asked Questions
What is Base64 encoding?
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 is commonly used to embed binary data in text-based formats like JSON, XML, HTML, and email bodies where raw binary is not allowed.
Does Base64 encoding encrypt my data?
No. Base64 is an encoding scheme, not an encryption method. Anyone can decode a Base64 string back to its original content. It provides no security or confidentiality. If you need to protect sensitive data, use proper encryption before encoding.
Why does Base64-encoded data become larger?
Base64 encoding increases data size by approximately 33% because it represents every 3 bytes of input as 4 ASCII characters. This trade-off is necessary to ensure the data can be safely transmitted through text-only channels.
How does the auto-detect feature work?
The auto-detect mode checks whether your input is a valid Base64 string by testing if it matches the expected character set and can be successfully decoded. If it appears to be Base64, the tool decodes it; otherwise, it encodes the input.