Convert numbers between binary, octal, decimal, and hexadecimal bases.
Type the number you want to convert to another base.
Choose binary, octal, decimal, hexadecimal, or custom base.
See the number converted to multiple bases simultaneously.
Number Base Converter rewrites a numeral among base 2 (binary), base 8 (octal), base 10 (decimal), and base 16 (hexadecimal). Identify the base in which the input is written; the tool interprets those digits by their positional weights and presents equivalent forms in the other supported bases. The frequent mistake is assuming a digit string has one universal value. It does not: 10 means two in binary, eight in octal, ten in decimal, and sixteen in hexadecimal.
A concrete input and expected output from the current implementation.
Input
25, with decimal selected as the source base
Expected output
Binary: 11001 Octal: 31 Decimal: 25 Hexadecimal: 19
In binary, 11001 is 16 + 8 + 1. Octal 31 is 3 * 8 + 1, and hexadecimal 19 is 1 * 16 + 9, so every representation has the decimal value 25.
The selected source base controls which digits are meaningful and what each position weighs. Starting at the right, positions represent successive powers of that base. Binary permits 0 and 1, octal permits 0 through 7, decimal permits 0 through 9, and hexadecimal adds A through F for values ten through fifteen. A digit outside the relevant alphabet cannot belong to that numeral.
Once the numeral's value is established, the converter rewrites it with the destination base's digit alphabet. Representation length can change considerably: one hexadecimal digit covers the same range as four binary digits. Letter case in hexadecimal does not change the value, so 2A and 2a denote the same number even if the displayed result consistently uses only one case.
No. The source base gives the string its value. In binary, 10 equals decimal 2; in octal it equals 8; in decimal it equals 10; and in hexadecimal it equals 16. Select or label the source base before comparing results, especially when the numeral contains only 0 and 1 and therefore looks valid in every supported base.
No. It changes the written radix of a number; it does not decide that a value is an ASCII character, Unicode code point, byte sequence, color, or machine instruction. You can convert a numeric code with it, but interpreting what that code means requires the relevant encoding or data-format rules.
The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.
Convert CSV data into structured JSON arrays or objects with automatic type detection.
Transform JSON arrays and objects into downloadable CSV spreadsheet format.
Convert YAML configuration files to JSON format with validation and formatting.
Parse XML documents and convert them to equivalent JSON structure with attributes.
Convert tab-separated values to comma-separated format with proper escaping.
Convert between Roman numerals and Arabic numbers with validation.