Formula and practical context.
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.
Formula, variables, and method
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. Start by identifying what each entered number represents and whether it is a measured value, a specification, or an assumption. Convert units before combining quantities, preserve full precision through intermediate steps, and round only the displayed result. For decoding, validate the alphabet and padding first, reconstruct each 24-bit group, then decode the resulting bytes as UTF-8. This sequence makes the output reproducible and helps expose a misplaced unit or decimal point before it affects a decision.
Worked example and independent check
Encoding the UTF-8 text “FigureNest” produces RmlndXJlTmVzdA== and decoding that value restores the original text. To check the example independently, write the formula first, substitute the values with their units, and complete one operation at a time. Compare the order of magnitude with a familiar reference rather than accepting a formatted result automatically. For decoding, validate the alphabet and padding first, reconstruct each 24-bit group, then decode the resulting bytes as UTF-8. If a second method or inverse calculation is available, use it to recover an original input. Small differences from hand calculation should come only from displayed rounding, not from a different definition.
Units and result interpretation
Text is converted to UTF-8 bytes before encoding. Four Base64 characters normally represent three input bytes, with equals signs used as padding. Base64 represents binary bytes with a restricted text alphabet; it does not hide, encrypt, or authenticate the data. A unit is part of the quantity, not a label added after the arithmetic. Keep decimal and binary prefixes, temperature scales, elapsed-time units, and electrical prefixes explicit. When comparing two scenarios, change one assumption at a time and retain the same unit convention. The result describes only the relationship named by this calculator; it does not automatically establish capacity, safety, compatibility, quality, or compliance.
Validation and boundary cases
Malformed alphabet characters, invalid padding, or decoded bytes that are not valid UTF-8 produce an explicit error. Blank values, malformed text, non-finite numbers, impossible ranges, zero divisors, and unsupported combinations receive an explicit message rather than a silent fallback. Boundary values are checked before the formula runs. If an input comes from a specification sheet, weather report, network plan, or measurement instrument, confirm its definition and precision. A syntactically valid value can still be unsuitable for the real situation, so inspect the assumptions alongside the result.
Assumptions, privacy, and practical limits
Base64 expands data by roughly one third and must not be treated as protection for passwords, personal data, tokens, or secrets. Encoding and decoding happen in this browser. Encoding is not encryption, and FigureNest does not send or store the entered value. Use the result as a transparent estimate or transformation, keep the source values with any saved result, and consult the linked authoritative material for definitions and applicability. For safety-critical, health-adjacent, security, network, chemical, or electrical work, verify the result with current standards, official warnings, qualified professionals, and appropriate test equipment.
Check assumptions and sources.
Base64 expands data by roughly one third and must not be treated as protection for passwords, personal data, tokens, or secrets.
Common 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.