Base64 Encoder & Decoder

Free Base64 Encoder and Decoder

Convert text to Base64 or decode a Base64 string with this free online Base64 tool. Base64 is commonly used to represent data with a limited set of text characters, such as when binary information needs to travel through systems designed around text. Developers often encounter Base64 in API payloads, data URLs, email formats, configuration examples and debugging output.

Encode and decode Unicode text

The encoder converts text to UTF-8 bytes before creating the Base64 representation. This is important because ordinary browser Base64 functions work directly with byte strings, not every Unicode character as a standalone value. Using UTF-8 allows common accented characters, non-English text and emoji to be encoded and decoded correctly when the input is valid. If the Base64 input is malformed or the decoded bytes are not valid UTF-8, decoding may return an error rather than silently changing the data.

How to use the Base64 converter

1. Paste or type your original text in the input box.
2. Choose Encode to create a Base64 string, or Decode to read a Base64-encoded UTF-8 string.
3. Review the result and use Copy output or Download result when needed.
4. Use “Use output as input” to move the result into the input box for another operation.

Base64 is not encryption

Base64 does not provide confidentiality, authentication or password protection. It is easy to reverse, so never treat an encoded value as a secret. Do not rely on Base64 to protect passwords, API keys, session tokens, personal records or confidential business data. If you need confidentiality, use an appropriate encryption method and manage keys securely. If you need to verify that data has not changed, use a suitable cryptographic integrity mechanism rather than encoding alone.

Common Base64 uses and limitations

Base64 output is usually larger than the original binary data, often by roughly one third before any additional formatting. It can be useful for embedding small assets in data URLs or transporting bytes through text-oriented systems, but it is not automatically a space-saving format. Some systems require padding characters, line breaks or URL-safe Base64 variants that replace certain characters. This page uses the standard Base64 alphabet; check your target system's requirements before using the output in a URL, token or protocol.

Privacy and safe handling

Encoding and decoding take place locally in your browser, and this tool does not upload your text to a FreeKitTools processing endpoint. Even so, avoid entering secrets into any tool unless you understand the environment and have authorization. For binary files or very large inputs, use a file-oriented tool or local development library. Always test the result in the system that will consume it, especially when working with API requests or production configuration.