Number Base Converter
Convert integers between binary, octal, decimal, and hexadecimal using arbitrary-precision BigInt arithmetic. Signed numbers and 0b/0o/0x prefixes supported. Runs entirely in your browser.
// Converted values will appear here…
About Number Base Converter
This free online number base converter translates integers between the four most common numeric bases — binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). Powered by JavaScript's BigInt, it handles arbitrarily large numbers without loss of precision. Accepts 0b, 0o, and0x prefixes and allows underscores as digit separators.
Common Use Cases
Reading bitmasks and flag enums, decoding packed binary protocols, inspecting hex-encoded identifiers (object IDs, color codes, memory addresses), auditing low-level encodings, and teaching introductory computer science concepts.
Key Benefits
- Arbitrary precision: Uses BigInt — safe for numbers beyond 2⁵³
- Signed support: Negative integers handled transparently
- Prefix aware: Accepts 0b, 0o, 0x and strips underscores
- Four bases: Convert once, see all four results
- Fully private: Everything runs locally — no network calls
Instant conversion
All four bases computed from a single input in milliseconds.
Fully private
Everything runs locally — safe for sensitive identifiers and bitmasks.
BigInt precision
Convert integers of any size without the usual 2⁵³ JavaScript limit.