How the Base64 Encode / Decode Tool works.
Base64 maps each 24 input bits to four 6-bit alphabet indexesInput text is represented as UTF-8 bytes; Base64 output uses A–Z, a–z, 0–9, plus, slash, and optional equals padding.
Worked example for the Base64 Encode / Decode Tool.
Encoding the UTF-8 text “FigureNest” produces RmlndXJlTmVzdA== and decoding that value restores the original text.
How to read this result.
Base64 represents binary bytes with a restricted text alphabet; it does not hide, encrypt, or authenticate the data.
How this tool gets the answer
Base64 maps each 24 input bits to four 6-bit alphabet indexes. Input text is represented as UTF-8 bytes; Base64 output uses A–Z, a–z, 0–9, plus, slash, and optional equals padding. Base64 represents binary bytes with a restricted text alphabet; it does not hide, encrypt, or authenticate the data.
A useful example
Encoding the UTF-8 text “FigureNest” produces RmlndXJlTmVzdA== and decoding that value restores the original text. A quick way to verify the calculation is: For decoding, validate the alphabet and padding first, reconstruct each 24-bit group, then decode the resulting bytes as UTF-8.
What the result tells you
Base64 represents binary bytes with a restricted text alphabet; it does not hide, encrypt, or authenticate the data. Text is converted to UTF-8 bytes before encoding. Four Base64 characters normally represent three input bytes, with equals signs used as padding.
Where the answer can go wrong
Malformed alphabet characters, invalid padding, or decoded bytes that are not valid UTF-8 produce an explicit error. Base64 expands data by roughly one third and must not be treated as protection for passwords, personal data, tokens, or secrets.
Privacy and practical use
Encoding and decoding happen in this browser. Encoding is not encryption, and FigureNest does not send or store the entered value. Keep the source value and its unit with any result you save so you can reproduce the calculation later.
Inputs and edge cases to check.
Malformed alphabet characters, invalid padding, or decoded bytes that are not valid UTF-8 produce an explicit error.
What this tool does not include.
Base64 expands data by roughly one third and must not be treated as protection for passwords, personal data, tokens, or secrets.
Reference guidance and methodology.
Base64 Encode / Decode Tool questions.
What does the Base64 Encode / Decode Tool do?
Encode Unicode text as Base64 or decode valid Base64 back to UTF-8 locally.
How can I check the result?
For decoding, validate the alphabet and padding first, reconstruct each 24-bit group, then decode the resulting bytes as UTF-8.
Which units and assumptions matter?
Text is converted to UTF-8 bytes before encoding. Four Base64 characters normally represent three input bytes, with equals signs used as padding. Base64 expands data by roughly one third and must not be treated as protection for passwords, personal data, tokens, or secrets.
Are the entered values sent or stored?
Encoding and decoding happen in this browser. Encoding is not encryption, and FigureNest does not send or store the entered value.