Skip to content
ProgrammerKit

Roman Numeral Converter

Convert between Roman numerals and Arabic numbers.

Free · Runs in your browser · Last updated

ROMAN
DECIMAL

About this tool

Convert any integer 1–3999 to Roman numerals and back. Validates input and explains each step.

Privacy

All processing for Roman Numerals happens locally inside your browser using JavaScript. Your input is never uploaded to a server, logged, or shared with third parties.

Frequently asked questions

Is the Roman Numerals free to use?

Yes. Roman Numerals is completely free for both personal and commercial projects. There are no usage limits, no sign-up, and no premium tier.

Is my data safe when I use Roman Numerals?

All processing happens locally in your browser using JavaScript. Your input is never uploaded to our servers, logged, or shared with any third party.

Does Roman Numerals work offline?

Once the page has loaded, the tool runs entirely client-side. You can disconnect from the internet and it will keep working in the same browser tab.

Which browsers are supported?

Roman Numerals works in all modern browsers, including the latest versions of Chrome, Firefox, Safari, Edge, Brave, and Opera, on desktop and mobile.

Do I need to install anything?

No. Roman Numerals runs in any modern web browser with no installation, browser extension, or account required.

More developer tools

Compare Anything
Side-by-side diff for JSON, XML, contracts, specs, job offers — with decision matrix.
JSON Formatter
Format, beautify, minify and validate JSON instantly in your browser.
XML Formatter
Pretty-print, minify and validate XML documents online.
YAML Formatter
Validate and re-emit YAML in a clean normalized form.