Number Base Converter

Free Number Base Converter

Convert positive integers between any pair of bases from 2 to 36. Common bases (binary, octal, decimal, hex) are always shown, with a custom base picker for everything else.

Common Uses

• Convert hex colors to decimal for math
• Translate binary flags during debugging
• Convert IP octets to binary
• Solve homework across number systems
• Inspect register values in embedded work

How It Works

Parsing uses JavaScript's parseInt with the source radix and converts via Number.prototype.toString into the target base. Common bases are pre-rendered for one-glance reading.

Privacy

All conversion runs in your browser. Nothing is uploaded.

Related: Binary to Decimal, Hex to Decimal, Hex to Text.

Two's Complement for Negatives

two's complement: flip every bit, add 1. So in 8-bit, −1 becomes

Related free tools

• XML Formatter & Minifier — Beautify or minify any XML — SOAP, RSS, SVG, sitemap. Browser-based parser.
• XML to JSON Converter — Parse any well-formed XML into a clean JSON tree with attributes and arrays.
• JSON to XML Converter — Convert JSON to well-formed XML — supports attributes, custom root, declaration.
• CSV Viewer — Open CSV or TSV files in your browser — sort, search, paginate, export filtered view.
• JSON to CSV Converter — Convert JSON data to CSV format. Export to spreadsheets easily.
• CSV to JSON Converter — Convert CSV data to JSON format. Useful for API development.
• JSON Formatter — Format, beautify, or minify JSON with customizable indentation.
• JSON Validator — Validate JSON syntax and find errors with line and column numbers.
• HTML Minifier — Compress HTML by removing comments, whitespace, and line breaks.
• CSS Minifier — Minify CSS by stripping comments, whitespace, and unnecessary characters.
• JavaScript Minifier — Compress JavaScript by removing comments, whitespace, and empty lines.
• Base64 Encoder/Decoder — Encode text to Base64 or decode Base64 back to text. UTF-8 support.