All tools · 🔄 Convert
🔢 Number Base Converter
Convert any integer between binary, octal, decimal, and hex. Useful for low-level programming, bitwise debugging, and reading hex color codes.
Examples
2550b11111111 · 0o377 · 255 · 0xFF0b1010100xff11111111 · 255Frequently asked questions
Why is 0x the hex prefix?
C language convention adopted by most modern languages. 0b for binary and 0o for octal are also common. Decimal needs no prefix.
Why does hex use 0-9 and A-F?
Base 16 needs 16 unique digits. We borrow A-F for 10-15 because they are familiar single characters. Some old systems used I-N or other alternatives.
When do I actually use these?
Hex: colors, memory addresses, RGB values. Binary: bitwise flags, low-level protocols. Octal: legacy Unix file permissions (chmod 755).
About this tool
Number Base Converter runs entirely in your browser using standard Web APIs. No data is sent to any server. The source for this tool is in our public GitHub repository.
Related tools
- 🔢 Hex ↔ ASCII / Text — Convert text to hexadecimal byte sequence and back. UTF-8 aware.
- Ⅻ Roman Numeral Converter — Convert between Roman numerals (I, V, X, L, C, D, M) and Arabic numbers.
- 📏 Unit Converter — Convert length, weight, temperature, area, volume, speed, time, energy.
Why this tool
vs typical free web-tool sites
| 1vw | Typical free site | |
|---|---|---|
| Price | Free | Free |
| Signup required | No | Often (for premium features) |
| Ads inside the tool | No | Yes (banner + video) |
| Data sent to server | No (browser-only) | Yes (inputs analyzed for ads) |
| Total tools | 96 | Often <20 or scattered across sites |
| Bookmarkable URL per tool | Yes | Mixed |
| Loads in under 1s | Yes (static) | Often slow (ad tracking) |
| Multilingual | EN / ES / PT / FR / DE | Usually EN only |
| Open source | Yes | No |