Add Line Numbers to Text Online Free — Instant

Add Line Numbers — prefix each line with a number error runs in your browser · nothing uploaded

Start Sep

⌃⏎ run · ⎋ clear · / focus input

TEXT ⇅ upload

⇅ drop a file to load it

NUMBERED

send output to

no matches

Handles pastes up to ~5MB smoothly in your browser — bigger files still work, just budget a second or two.

Add Line Numbers Online

Updated 2026-07-09

Add line numbers to text online for free. Paste any text and SnapTools prefixes each line with a sequential number and the separator you choose — instantly, in your browser. Nothing is uploaded.

Numbering lines by hand is tedious and breaks the moment you insert a line. This tool renumbers the whole block in one step, with a configurable starting number for snippets that continue from elsewhere and a choice of separator to match your style — a dot for a list, a colon for references, a tab for data. Copy the result straight into documentation, steps, or a checklist.

// how to use

1 Paste your text into the input panel on the left.
2 Choose a starting number and the separator between the number and each line.
3 Read the numbered text on the right, then copy or download it.

// examples

Number each line

Input

first
second
third

Output

1. first
2. second
3. third

Custom separator

Input

alpha
beta

Output

1: alpha
2: beta

// common uses

Numbering a list or set of steps Referring to specific lines when reviewing text Preparing numbered output for documentation Creating ordered checklists from plain lines

// faq

No. Numbering runs entirely in your browser, so your text never leaves your machine.

Yes. Line numbers usually start at 1, but you can begin from any number — useful when a snippet continues from a larger file.

Yes. Pick what goes between the number and the line — a dot and space, a colon, a parenthesis, or a tab — to match the style you need.

Every line is numbered in sequence, including blank ones, so the numbering stays aligned with the original line positions.

To strip a leading number pattern, use the Find & Replace tool with a regular expression that matches the prefix you added.

// related

Remove Line Breaks Sort & Dedupe Lines Character & Word Counter Remove Duplicate Lines Find & Replace

Use this via API

Get a free API key →

curl -X POST https://snaptools.dev/api/v1/tools/add-line-numbers \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"text":"first second third"}'