This Base64 encoder and decoder lets you convert any text to its Base64 representation or decode a Base64 string back to readable text. It handles Unicode characters including emojis correctly by using UTF-8 encoding under the hood. Everything runs entirely in your browser, so your data never leaves your device.
Enter your values to see the result.
Hello, World! → SGVsbG8sIFdvcmxkIQ==
A simple ASCII string encoded to its Base64 representation.
SGVsbG8sIFdvcmxkIQ== → Hello, World!
Decoding the Base64 string returns the original text.
🎉 → 8J+OiQ==
Emoji characters are correctly encoded using UTF-8 byte sequences.
8J+OiQ== → 🎉
The Base64 representation of the emoji decodes back perfectly.
Base64 is one of the most common encoding schemes used in web development and data transmission. It converts binary data into a text representation using a set of 64 ASCII characters: uppercase A through Z, lowercase a through z, digits 0 through 9, plus sign and forward slash. The equals sign serves as padding when the input data length is not a multiple of three bytes.
The primary reason Base64 exists is compatibility. Many older protocols and systems were designed to handle only text data, not raw binary. Base64 provides a way to represent any binary content as safe ASCII text that can pass through these systems without corruption. Email systems, for example, use Base64 to attach files to messages. Web developers use it to embed images directly in CSS or HTML through data URIs.
This Base64 encoder and decoder operates entirely in your browser. When you encode text, the tool first converts your input to UTF-8 bytes using the TextEncoder API, then converts those bytes to a binary string, and finally applies the standard btoa function to produce the Base64 output. This two-step process ensures that Unicode characters, including emojis and non-Latin scripts, are handled correctly.
When you decode a Base64 string, the process works in reverse. The tool uses atob to convert the Base64 string back to a binary string, then converts those bytes into a Uint8Array, and finally decodes them using the TextDecoder API to reconstruct the original UTF-8 text. If the input is not valid Base64, the tool displays a clear error message instead of crashing.
Developers encounter Base64 in many everyday situations. Data URIs allow you to embed small images directly in your HTML or CSS, reducing HTTP requests. The format looks like data:image/png;base64,iVBOR.... API authentication often uses Base64 to encode credentials in the Authorization header for HTTP Basic Auth. JSON Web Tokens (JWTs) use a Base64 variant called Base64URL to encode their header, payload and signature segments.
Content management systems and email clients use Base64 to handle binary attachments. When you attach a file to an email, the attachment is typically Base64-encoded before transmission. Similarly, when a web application needs to store binary data in a text-only format like JSON or XML, Base64 provides a reliable encoding that preserves the data integrity through the conversion.
All encoding and decoding operations happen locally in your browser. Your input is never sent to any server, never stored in any database, and never analyzed by any third party. The JavaScript that performs the conversion runs entirely on your device, making this tool safe for handling sensitive data like API keys, authentication tokens, or any other confidential content you need to encode or decode.
It is important to remember that Base64 is not encryption. It provides no security whatsoever — anyone who sees a Base64 string can decode it instantly. If you need to protect sensitive data, use proper encryption tools instead. Base64 is purely a data format conversion tool designed for compatibility and transport, not for confidentiality.
Base64 is a binary-to-text encoding scheme that represents binary data as an ASCII string. It uses a set of 64 characters consisting of uppercase letters, lowercase letters, digits, plus sign and forward slash. Base64 is commonly used to encode binary data for transmission over text-based protocols like email or embedding images in CSS and HTML files.
No, Base64 is not encryption. It is an encoding scheme that converts data into a different representation, but it does not provide any security or confidentiality. Anyone can decode a Base64 string back to its original form without needing a key or password. Base64 is used for data compatibility, not for protecting sensitive information from unauthorized access.
Yes, this tool correctly handles Unicode characters including emojis, accented letters, CJK characters and other scripts. It works by first converting the input text to UTF-8 bytes before encoding to Base64, and by decoding the Base64 back to UTF-8 bytes before converting to text. This ensures full compatibility with any character set you might need to encode or decode.
The equals signs at the end of a Base64 string are padding characters. Base64 encodes data in groups of three bytes into four characters. When the input length is not a multiple of three, padding characters are added to make the output length a multiple of four. One equals sign means one padding byte was needed, and two equals signs mean two padding bytes were needed.
No, all encoding and decoding happens entirely in your browser using JavaScript. Your text is never transmitted over the network, never stored, and never processed by any third party. You can safely paste sensitive data like API keys, tokens or credentials without any risk of the content being exposed or logged on a remote server.
Base64 is widely used for embedding images directly in CSS or HTML files using data URIs, encoding binary attachments in email messages, transmitting small binary payloads in JSON or XML APIs, and storing complex data in URL parameters. Developers also use it to encode credentials for HTTP Basic Authentication headers and to represent binary data in configuration files that only support text.
Last updated on 2026-09-26 · Written by UtiliaTools