Base64 Encoder
Encode any text to Base64 instantly in your browser. Free, no signup.
How to use this tool
- Enter text to encode in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your base64 output and the full breakdown beneath it.
Base64 is a binary-to-text encoding scheme widely used to transmit data in text-safe formats such as email, URLs, and JSON payloads.
How it works
This tool converts plain text into Base64-encoded form. Base64 is a binary-to-text encoding scheme that represents data using 64 printable ASCII characters (A-Z, a-z, 0-9, +, and /). It is widely used to safely transmit binary data or text through systems that only handle text, such as email and HTTP headers.
Paste or type any text into the input field and click Encode. The tool immediately outputs the Base64 string. The encoding works by grouping the input bytes into sets of three, then representing each group as four Base64 characters. If the input length is not a multiple of three, padding characters (=) are added at the end.
Common use cases include encoding credentials for HTTP Basic Authentication headers, embedding small images or fonts directly in CSS as data URIs, passing structured data through URL parameters, and encoding JSON payloads in JWT tokens.
This tool operates entirely in your browser -- your text is never sent to a server. It handles standard UTF-8 text input and produces standard Base64 output compatible with all major programming languages and APIs.
Worked example
Encode credentials for a Basic Auth header
- Type your credentials: myuser:mysecretpassword
- Click Encode
- Copy the result: bXl1c2VyOm15c2VjcmV0cGFzc3dvcmQ=
- Use it in your HTTP header: Authorization: Basic bXl1c2VyOm15c2VjcmV0cGFzc3dvcmQ=
bXl1c2VyOm15c2VjcmV0cGFzc3dvcmQ=
Common mistakes to avoid
- Treating Base64 as a security measure -- it provides no confidentiality and is trivially reversible.
- Copying the Base64 output with extra whitespace or line breaks, which can cause decoding failures in strict parsers.
- Encoding an already-encoded Base64 string a second time, producing double-encoded output that is difficult to reverse.
Key terms
- Base64
- An encoding scheme that represents binary or text data using 64 printable ASCII characters, producing output that is safe to use in text-based protocols.
- Padding (=)
- One or two equals signs appended to Base64 output when the input length is not a multiple of three bytes, ensuring the output length is a multiple of four characters.
- Data URI
- A URI scheme that embeds file content (such as an image) directly in a document as a Base64 string, removing the need for a separate HTTP request.
Frequently asked questions
- What is Base64?
- Base64 encodes binary or text data into a 64-character ASCII subset, making it safe for transmission in text-based systems.