Add Prefix To Lines
Add a custom prefix to the start of every line. Useful for formatting lists, adding markers, or bulk editing text.
Input
Output
Tip: You can verify in DevTools → Network that nothing is uploaded.
About this Add Prefix To Lines
Add Prefix To Lines transforms your text instantly according to specific rules. This tool processes your input locally in your browser.
Use this tool to clean, format, or prepare text for your workflow. All processing happens locally — nothing you paste is sent to a server.
- Process text data quickly without external tools
- Transform content for development workflows
- Clean and format text for analysis
- Enable Auto to transform as you type
- Upload text files directly from your device
- Download the result when done
FAQ
No. Everything runs locally in your browser. Nothing you paste is sent to a server.
After the page loads once, it will typically keep working offline (unless you hard refresh with no cache).
No. Your input stays in your browser. Only optional preferences like theme or language may be stored.
Any plain text. You can paste text directly into the input box.
Yes. The prefix is added to each line, typically including empty lines.
No. It is only added at the start of each line.
Yes. Any characters you enter are used exactly as the prefix.