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Line Numberer

Add line numbers — or strip the ones you pasted in by accident.

Runs in your browserNo sign-upNo file limitAPI available
0 chars · 0 lines
Options

0 auto-sizes to the largest number, so the text stays aligned.

Result

Start typing above and the result appears here.

How to use Line Numberer

  1. Paste your lines

    Any line ending works — CRLF, LF or CR.

  2. Set the numbering

    Zero-padding keeps the text aligned once you pass line 9, which is what makes a numbered list readable in a monospace font.

  3. Or strip numbers instead

    Switch to remove mode to clean up text copied out of a code sample, a log viewer or a PDF.

Why use this line numberer

  • Runs on your device

    Your input is handled entirely in this browser tab. Nothing is uploaded, so there is nothing for us to store, log or leak.

  • No sign-up, no quota

    No account, no daily limit, no watermark and no email wall. Use it once or two hundred times a day.

  • Built to be linked

    Options are stored in the URL, so a configured tool is a link you can send to a colleague or bookmark.

Technical notes

Every competitor adds line numbers. Almost none remove them, which is the direction people actually need more often — you copy a snippet out of a documentation page or a log viewer and the numbers come with it. This tool does both, and its stripper recognises six separator styles rather than assuming one.

Numbered formats the remove mode recognises

Pasted formatExampleRecognised
Dot1. const x = 1Yes
Colon42: const x = 1Yes
Bracket7) const x = 1Yes
Pipe (log viewers)128 | const x = 1Yes
Tab (GitHub copy)15⇥const x = 1Yes
Aligned columns 9 const x = 1Yes
Trailing numbersconst x = 1 // 15No — ambiguous with real content

Supported

  • Custom start, step, zero-padding and separator
  • Prefix and suffix on every line
  • Blank lines skipped or numbered, your choice
  • Removal of six common numbered formats
  • CRLF, LF and CR input

Limits and trade-offs

  • Removal is pattern-based, so a line genuinely starting with a number and a separator will lose it. The changed-line count makes that visible.
  • Numbers are added as literal text, not as a gutter — pasting the result back into an editor includes them.

Last verified August 2026 · benchmarks re-run each quarter.

Frequently asked questions

How do I remove line numbers from copied code?

Switch the mode to "remove existing line numbers". It strips a leading number followed by a common separator — a dot, colon, bracket, pipe, tab or two-plus spaces — and leaves the rest of the line untouched, including its indentation.

Why would I zero-pad the numbers?

Without padding, line 9 and line 10 start at different columns and the text jumps left and right. Padding to a fixed width keeps everything aligned, which matters as soon as you have more than nine lines in a monospace font.

Can I start from zero, or count in steps?

Yes. Start at any number including zero or a negative, and step by any amount — step 10 gives 10, 20, 30 for BASIC-style listings or test case IDs.

What happens to blank lines?

By default they stay blank and are not counted, so the numbering follows the content rather than the whitespace. Turn the option off if you want every physical line numbered including the empty ones.

Will removing numbers damage lines that start with a real number?

It can. A line like "2024 was a good year" begins with a number followed by a space, which matches the pattern. Check the result — the tool reports how many lines it changed so a surprising count is visible immediately.

Guide: how to use the Line Numberer, step by stepThe longer version — alternatives, trade-offs, and the mistakes that waste the most time.