Add Line Numbers

Adding line numbers to text by hand is slow and error-prone: one inserted or deleted line forces you to renumber everything below it. This free tool numbers every line of your text in a single click and renumbers just as fast when the content changes. Paste your text, choose a starting value and separator style, and copy the numbered result. It works for reference lists, code snippets, legal documents, transcripts, lyrics, survey questions, and any content where numbered lines make discussion and review easier. Everything runs in your browser, so even confidential text never leaves your device.

By default the tool starts numbering at 1, but you can begin at any value, which is useful when a numbered document continues across several files or when an existing list already occupies the first positions. The separator controls how the number attaches to the line: a period (1.) reads naturally in lists and outlines, a parenthesis (1)) is common in questionnaires and exams, a colon (1:) suits transcripts and chat logs, and a tab keeps the number visually separated from content in technical material. Pick the style that matches the destination document so the numbered output drops in without further editing.

When a list runs past nine items, single-digit and double-digit numbers no longer align, and the left edge of the text becomes ragged. The zero-padding option fixes this by widening every number to the same length: in a 120-line document, line five becomes 005 and line eighty becomes 080. The tool calculates the required width automatically from the total line count. Padded numbers are standard in code listings, log excerpts, and any monospaced context where vertical alignment matters for fast scanning.

Text often contains blank lines that separate paragraphs or groups of items, and whether those lines should consume a number depends on the purpose. With the skip option enabled, blank lines are preserved in the output but receive no number, so the numbering counts only meaningful content — the right choice for lists and questionnaires. With the option disabled, every physical line is numbered, which matches how code editors and legal line-numbering conventions count lines. The tool leaves the blank lines themselves intact either way; it only decides whether they advance the counter.

Editors and reviewers number manuscript lines so feedback can reference an exact location instead of quoting passages. Teachers number reading excerpts and exam questions for classroom discussion. Developers paste numbered code fragments into documentation, bug reports, and code reviews where line references replace lengthy explanations. Legal professionals number contract clauses and deposition transcripts for citation. Researchers number interview transcripts before coding qualitative data. In each case, stable line numbers turn vague references like the paragraph near the end into precise ones like line 47.

The biggest cost of manual numbering appears when the text changes: inserting one line near the top invalidates every number after it. With this tool, renumbering is free — remove the old numbers if needed, make your edits, and apply numbering again in one click. A practical workflow is to keep the master text unnumbered in your editor and number a copy here whenever you need to share or print it. Paired with the companion Remove Line Numbers tool, you can move text in and out of its numbered form as often as the document evolves.

All numbering happens locally in your browser with JavaScript. The text you paste is never uploaded, logged, or stored on a server, which makes the tool safe for contracts, unpublished manuscripts, internal documentation, and other sensitive material. Closing or refreshing the page removes the text from memory entirely. There are no length limits beyond what your browser can handle, so multi-page documents number just as quickly as a short list.