Roman Numeral Converter

WHAT IT DOES

Roman Numeral Converter translates between Arabic numbers (1-3999) and Roman numerals. Enter a number like 2024 and see it converted to MMXXIV, or enter a Roman numeral like MCMXCIX and get the Arabic value 1999. The tool validates input, detects errors, and shows clear error messages. A reference chart displays the values of all Roman numeral symbols (I, V, X, L, C, D, M) and common subtractive combinations (IV, IX, XL, XC, CD, CM). Real-time conversion updates as you type, and you can copy results with one click.

WHERE IT RUNS

The extension runs entirely within your browser's local environment using the BotGentz framework. All number parsing, roman conversion, and validation occur on your machine without any network requests. No number data, conversion history, or user activity is ever transmitted, uploaded, or stored externally. The tool works on any website and respects the browser's security boundaries, operating within the isolated extension sandbox. Roman numeral conversion uses standard Roman numeral rules and validation.

HOW TO USE

Click the extension toolbar icon to open the Roman Numeral Converter panel. Enter a number (1-3999) or a Roman numeral in the input field. The conversion result appears instantly if auto-convert is enabled. The output shows the converted value with an arrow indicating the direction. Click "Convert" to manually trigger a conversion. Click "Copy Result" to copy the converted value to your clipboard. The reference chart shows all Roman numeral symbols and their values for quick reference. Toggle "Auto convert" to enable or disable real-time conversion. Toggle "Uppercase output" to control whether Roman numerals are displayed in uppercase or lowercase. Toggle "Show reference chart" to show or hide the reference chart. Toggle "Strict validation" to enforce standard Roman numeral form (e.g., rejecting IIII instead of IV). The panel displays validation errors for invalid inputs.

THE ROMAN CONVERSION ENGINE — WHY IT WORKS

Most Roman numeral converters use simple mapping tables that can produce invalid numerals or fail to validate input. This tool uses a two-directional conversion engine with strict validation. For Arabic-to-Roman conversion, the engine uses a greedy algorithm that iterates through a descending list of Roman values (1000, 900, 500, etc.), subtracting each value from the input number and appending the corresponding Roman symbol until the number reaches zero. For Roman-to-Arabic conversion, the engine scans the Roman numeral string left to right, detecting two-character subtractive combinations (CM, CD, XC, XL, IX, IV) first, then single characters, and accumulates the total. The strict validation option uses a regular expression to ensure the Roman numeral follows the standard form (e.g., M{0,3}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})). This dual-direction approach ensures accurate conversion and proper validation.

THE PANEL

The Roman Numeral Converter panel is fully draggable by its title bar and remembers its position on screen per website. It snaps to the edges of your browser window for clean alignment. Collapse the panel to a compact icon strip using the minimize button, restoring it with a single click. Resize the panel by dragging any edge or corner; the input area, output display, and reference chart adjust proportionally. Press the Escape key to close the panel instantly. The panel maintains independent state for each browser tab, allowing you to convert Roman numerals in multiple tabs simultaneously.

PLEASE NOTE

This extension requires the free BotGentz extension framework to be installed and enabled. The tool supports numbers from 1 to 3999 only, as larger numbers require special notation not covered by standard Roman numerals. The strict validation option enforces standard Roman numeral form; disabling it allows some non-standard forms but may produce unexpected results. The reference chart shows the most common Roman numeral symbols and subtractive combinations. All conversion data is processed locally and is never transmitted, logged, or shared. The extension requests no network permissions and functions entirely offline. The source code is fully auditable and available for review.