Roman Numerals
Numbers ↔ Roman numerals (1–3999).
Input
Output
About this tool
Numbers ↔ Roman numerals (1–3999). Everything happens locally in your browser — the text you paste is never sent to a server, which is why it works offline and why it is safe for tokens, keys and production data.
How it works
The tool transforms your input directly in the page: type or paste on the left, read the result on the right. Options apply immediately. Output can be copied or downloaded as a text file.
Is my data uploaded anywhere?
No. There is no backend for this tool — the code runs in the page, so nothing leaves your device.
Does it work offline?
Once the page has loaded it keeps working without a connection.