Add Line Numbers
Prefix every line of text with a sequential number.
This tool runs entirely in your browser. Your data never leaves your device — nothing is uploaded to our servers.
Add Line Numbers — free online text tools
Prefix every line of text with a sequential number. Whether you need to numbering a single file or handle them in bulk, this free online text tools tool gives you a fast, no-nonsense result with no sign-up, no watermark and no software to install. Because Add Line Numbers runs entirely inside your browser, your files are never uploaded to a server — the whole process happens on your own device, so it stays completely private and works even on slow connections.
- 100% free — no subscription, no credit card and no hidden limits.
- No account required; sign in only if you want to save your history and favorites.
- Fully private — files are processed locally in your browser and never leave your device.
- Works in any modern browser on desktop and mobile — installable as a fast PWA.
- Clean output with no watermarks added to your text tools files.
How to add line numbers
- 1
Open the Add Line Numbers tool and paste or drop your content into the input area.
- 2
Adjust the available options to match exactly what you need.
- 3
Run the tool — add line numbers completes instantly in your browser.
- 4
Preview the result, then copy it or download the output file.
Frequently asked questions
Is the Add Line Numbers tool free to use?+
Yes. Add Line Numbers is completely free with no watermarks, no sign-up requirement, and no file-size paywall. Create a free account only if you want your history and favorites saved.
Is my data safe with the Add Line Numbers tool?+
Absolutely. Add Line Numbers runs entirely in your browser — your files and text never leave your device and nothing is uploaded to our servers.
How do I add line numbers online?+
Open this page, drop or paste your content into the Add Line Numbers tool, choose your options, and the result is generated instantly in your browser — then download or copy it. No installation or upload needed.
Is there a file size or usage limit?+
There is no per-file paywall. Because Add Line Numbers runs on your own device, the practical limit is your browser's available memory rather than an artificial cap — most everyday text tools files process instantly.
Do I need to install anything to add line numbers?+
No installation needed. Add Line Numbers works in any modern browser on Windows, macOS, Linux, Android and iOS, and can be installed as a lightweight web app (PWA) for one-tap access.
Does Add Line Numbers work on mobile?+
Yes. The tool is fully responsive and works on phones and tablets exactly as it does on desktop, so you can add line numbers on the go.
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