1. What does this tool do
This free online number converter converts numbers between binary, octal, decimal, hex, base 32, base 36, and base 64 in one place. Use it as a binary to decimal converter, hex to decimal converter, or decimal to hex for developers, students, and anyone working with different number systems. Enter a value in any base and see the equivalent in all others instantly. Supports negative numbers and very large integers (BigInt). Free and private; everything runs in your browser. Ideal for programming, hex colors, bit masks, or education.
2. How to use it
Quick start: Enter a number in the selected base (e.g. 255 decimal, FF hex), choose source base if needed, then view all base representations and copy the one you need.
- Enter input — Type a number in the selected base (e.g. 255 in decimal, FF in hex, 11111111 in binary).
- Select source base — Use the dropdown to choose which base your input is in (default: decimal).
- View outputs — All seven base representations appear with copy buttons.
- Copy — Click a format's copy button to use it in code, docs, or calculations.
3. How it works
Parsing: The input string is parsed digit-by-digit using the alphabet for the source base. Base 2–36 use standard digits (0–9, A–Z). Base 32 uses a Crockford-style alphabet; base 64 uses the standard Base64 charset. Conversion: The value is stored as BigInt. Output for each base is produced by repeated division, mapping remainders to the base's alphabet. All computation runs entirely in your browser. No data is sent to any server.
4. Use cases & examples
- Programming — Convert hex color codes, binary flags, or bit masks.
- Low-level work — Translate between binary, octal, and hex for debugging.
- Education — Explore number bases for computer science or math courses.
- Data encoding — Use base 32 or base 64 for compact numeric representation.
- API development — Verify numeric IDs or hashes in different encodings.
Example
255(decimal) → 11111111 (binary), 377 (octal), FF (hex)FF(hex) → 255 (decimal)-42(decimal) → -101010 (binary), -52 (octal), -2A (hex)
5. Limitations & known constraints
- Integers only — Fractions and decimals are not supported.
- Input length — Maximum 1,000 digits to avoid performance issues.
- Base 32 alphabet — Uses Crockford-style; excludes I, L, O, U to avoid confusion with 1 and 0.
- Base 64 — Case-sensitive;
aandArepresent different digits (10 vs 36).