This tool converts text to Base64 and back. It handles UTF-8 correctly, offers the URL-safe alphabet for tokens and file names, and reports invalid input instead of returning broken characters.
Your data is processed locally in your browser and is not uploaded to our server.
Text → UTF-8 bytes → 6-bit groups → Base64 alphabet
Each three bytes become four Base64 characters. A final group of one or two bytes is padded with =, unless the URL-safe variant is selected.
+ → -; / → _; padding removed
Standard Base64 uses + and /, which have meaning in URLs. The URL-safe variant substitutes - and _ and drops trailing = so the value can be placed in a query string or file name.
A short text needs to travel inside a JSON string.
Decoding the result returns the original sentence exactly, including punctuation.
A Base64 value will be used in a URL query parameter.
The output contains no characters that need percent-encoding in a URL.
Anyone can decode Base64. It only represents bytes in text form and must not be used to protect passwords or secrets.
Base64 can represent arbitrary binary data. If the bytes are not valid UTF-8, the decoder reports an error rather than showing replacement characters.
Whitespace is ignored when decoding, and missing padding is accepted. Invalid characters or an impossible length are rejected.
No. Base64 is an encoding, not encryption, and provides no confidentiality. Use encryption for secrets and Base64 only for transporting bytes in text.
Padding is optional for many decoders and = can be awkward in URLs. The URL-safe variant removes it while keeping the data unchanged.
Yes. Text is encoded as UTF-8 first, so emoji, Chinese, Cyrillic and accented characters round-trip correctly.
The bytes may not be valid UTF-8 text, or the string may contain a character outside the Base64 alphabet. Binary payloads need a file or hex tool instead.
No. Encoding and decoding happen entirely in your browser, and nothing is sent to a server.