Base64 Encode
Put plain text in the box to encode, or put a Base64 string in the box to decode. The result is a different writing of the same bytes. Base64 is not encryption. The Base64 guide explains that difference in more detail.
Limit: 400 KB. Ctrl or Cmd+Enter encodes.
What the encoder expects
Encode treats the input as Unicode text and writes UTF-8 bytes as Base64. Decode expects the usual alphabet A–Z, a–z, 0–9, plus, slash, and optional equals padding. Spaces in a Base64 string are ignored. If the length or the characters are wrong, the result box stays empty and the status line says so.
When this tool helps
Use Base64 when a protocol wants binary-safe text, such as a data URL or a token that must travel inside JSON. Do not use it to hide a password or a private note. Anyone who sees the string can decode it. If encode and then decode do not return the same text, the input was not valid Base64, or the original was not UTF-8 text this decoder can read.
Questions
Why did decode fail?
The string may be missing padding, use the wrong alphabet, or have a length that is not a multiple of four after spaces are removed.
Is this the same as encryption?
No. Encoding changes representation. Encryption needs a secret. Base64 has no secret.
Does the text leave this tab?
No. Encode and decode run in the browser.