Text ToolsRuns locally · No upload
Add Line Numbers
Number every line in text or code with configurable starting number. Useful for references, documentation, and code snippets.
Private by design
Everything runs in your browser. Your input is never uploaded, stored, or logged on our servers.
Works offline after load
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Frequently asked questions
Is this tool free?+
Yes. Every Utiliio utility is free with no sign-up, usage limits, or paywalls.
Do you store my data?+
No. Processing happens entirely in your browser. Your input never leaves your device.
Can I use this tool offline?+
Yes. Once the page loads, most tools continue working without an internet connection.