Base64 Encoder & Decoder
Encode and decode text as Base64 locally in your browser, with full Unicode and emoji support. Nothing is uploaded.
How to use
- 1Choose a modeChoose encode (text → Base64) or decode (Base64 → text).
- 2Enter contentPaste the text or Base64 value to convert. Chinese and emoji are supported.
- 3Copy the resultCopy the converted result in one click. Everything stays in your browser.
About Base64 encoding
Base64 represents arbitrary data with 64 text-safe characters: A–Z, a–z, 0–9, +, and /. It is not encryption. It lets binary data and special characters travel safely through text-only channels such as URLs, JSON, email, and configuration files. This tool converts both ways between text and Base64 and fully supports Chinese, Japanese, emoji, and other multibyte characters.
Base64 output is about one-third larger than the original data, and it is a public, reversible transformation that anyone can decode. Never treat it as encryption for passwords or sensitive information. For a deeper explanation, read What Is Base64? How It Works, Uses, and Caveats.
Common uses
- Data URLs: embed small icons directly in HTML or CSS as
data:...;base64,. - Email attachments: MIME uses Base64 to carry binary attachments.
- Binary data in JSON or config: convert it to a Base64 string before embedding it.
- API parameters: safely include data with special characters in a URL or request body.
Encoding and decoding happen locally, so your input never leaves your device. When working with API data, use the JSON formatter to clean up the response as well.
Frequently asked questions
QWill my text be uploaded?
No. Encoding and decoding happen entirely in your browser, so your content never leaves your device.
QDoes it support Chinese and emoji?
Yes. The tool uses UTF-8, so Chinese, emoji, and other multibyte characters are encoded and restored correctly.
QWhy does decoding fail?
The input may not be valid Base64, or the decoded bytes may not form valid UTF-8 text. Check that the full value was pasted without extra characters.
QCan pasted Base64 contain spaces or line breaks?
Yes. Whitespace is removed automatically before decoding.
QDo I need to sign up or pay?
No. The tool is completely free and requires no account.