About Base64 encoding
Base64 represents binary or text data using 64 safe ASCII characters, which makes it ideal for embedding data in URLs, JSON, data URIs, HTML and email. Developers reach for it constantly when debugging tokens, configuration values and API payloads. This converter handles full UTF-8, so emoji and non-English text are preserved exactly, and because it runs locally nothing you paste is ever uploaded.
Frequently asked questions
- How do I encode text to Base64?
- Pick Encode and type your text — the Base64 appears instantly, ready to copy.
- Does it support emoji and accents?
- Yes — full UTF-8 encoding and decoding, so everything round-trips correctly.
- Is my data sent anywhere?
- No. Encoding and decoding run in your browser; the tool works offline.
How Base64 Encoding Functions
Base64 works by transforming binary data into a string of 64 printable characters. The process takes three 8-bit bytes of input and maps them into four 6-bit chunks. Each 6-bit chunk corresponds to a specific index in a character table that includes uppercase letters, lowercase letters, digits, and two symbols, typically plus and forward slash. This transformation ensures that binary information remains intact when transmitted over systems that only support text.
The standard character set is defined in RFC 4648, which also specifies the use of the equals sign as a padding character. If the input data length is not a multiple of three bytes, padding is added to the end of the output to reach a length divisible by four. This mathematical constraint is why encoded strings are always approximately 33 percent larger than the original source data. Understanding this overhead is important when calculating storage requirements or bandwidth limits for payloads.
A common mistake is treating Base64 as a form of encryption or security. Because the encoding algorithm is public and deterministic, anyone can reverse the process without a key to view the original content. Another frequent error involves ignoring character encoding standards, specifically when dealing with multi-byte characters like emojis or non-Latin scripts. If the source text is not interpreted as UTF-8 before the encoding process begins, the output will represent the incorrect byte sequence and become corrupted.