Description
padCharacters = (3-byteCount modulo 3) modulo 3; encodedLength = 4*ceil(byteCount/3).
A positional encoding separates numeric digit values, alphabet symbols and final-block padding. An alphabet lookup is not a whole-stream codec, and character count can differ from the number of source bytes represented.
padCharacters = (3-byteCount modulo 3) modulo 3; encodedLength = 4*ceil(byteCount/3).
When to use this tool
Use Encoding: Base64 Pad Character Count when checking one alphabet mapping or bounded encoding-padding term.
How to use the tool and how it works
- Enter byteCount. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read result. Expand result to inspect the returned fields.
Require whole byteCount in [0,1000000000]. padCharacters = (3-byteCount modulo 3) modulo 3; encodedLength = 4*ceil(byteCount/3).1
Alphabet, tail pad bits and written padding depend on the selected base encoding. This tool handles only its stated local component.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| byteCount | Byte Count | Required. Safe integer. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| result | Object containing the named calculated members below. | Required. Object. |
| result.padCharacters | Pad Characters | Calculated result member: number. |
| result.encodedLength | Encoded Length | Calculated result member: number. |
{
"input": {
"byteCount": 1
},
"output": {
"result": {
"padCharacters": 2,
"encodedLength": 4
}
}
}Limitations and assumptions
- This assumes padded Base64 without whitespace or line breaks. A format that omits padding has a different written length; source text is not measured or encoded.
- Outputs are nested inside result. Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use the complete codec matching the intended alphabet and padding policy for real payloads and interoperability checks.
References
-
Calculation and input contract: encode/base64-pad-character-count — tool.io
-
Base16, Base32 and Base64: RFC 4648 — Internet Engineering Task Force
Similar or alternative tools
- Base64 Tail Pad Bit Count
Calculate Base64 tail-byte remainder, written padding count and unused pad-bit count.
- Encoding: Base32 Pad Character Count
padCharacters is [0,6,4,3,1][byteCount modulo 5]; encodedLength = 8*ceil(byteCount/5).