How to use this tool
- Choose Encode text or Decode Base64.
- Select the standard or URL-safe alphabet and paste the corresponding input.
- Run Convert Base64 and copy the output if it matches the format required by your application.
Understanding the output
Encoding first converts text to UTF-8 bytes, then represents those bytes with Base64 characters. Standard output includes padding when required. URL-safe output uses hyphens and underscores instead of plus and slash, and omits trailing padding.
For percent-encoding a query parameter instead of Base64, use the URL Encoder and Decoder and choose component encoding.
Encoding a short greeting
Hello becomes SGVsbG8= in standard Base64 and SGVsbG8 in URL-safe output. Decoding either with the appropriate alphabet returns Hello.
Encoding does not hide sensitive information
Base64 is a reversible representation, not encryption or a password-protection method. Anyone who has the encoded value can decode it. It is useful when a system expects text-safe transport of bytes, but it does not provide secrecy, integrity, or proof of who created the data.
A token containing several dot-separated pieces may use Base64url for individual segments, but decoding those segments does not verify a signature. Do not treat a readable payload as evidence that a token is trustworthy or authorized.
Know whether the underlying bytes are text
Base64 can represent any binary data, including images and compressed files. This utility is specifically for UTF-8 text. It rejects decoded byte sequences that are not valid UTF-8 instead of displaying replacement characters and pretending the content was recovered. Use a binary-aware file tool when the payload is an image, archive, or another nontext format.
Method and supported input
TextEncoder produces UTF-8 bytes. Base64 encoding uses the selected alphabet; decoding accepts optional missing padding and ignores whitespace before validating and decoding the bytes.
- Decoded content is intended to be UTF-8 text.
Limitations
- This tool does not decode images or other binary files.
- It does not verify signatures, decrypt data, or inspect token authenticity.
Common questions
Why does the URL-safe result have no equals sign?
This tool omits optional trailing padding in Base64url output. Standard Base64 output retains required padding.
Why does a valid-looking Base64 value fail to decode?
Its bytes may not be UTF-8 text, or it may use a different alphabet or malformed padding.