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TextArray1.41.0
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Multi-level outline numbering

Add hierarchical numbers like 1, 1.1 and 1.2 to an indented outline.

Input
Output
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Multi-level outline numbering
Paste an outline where each level is marked by indentation or a leading bullet, and this tool adds hierarchical numbers like 1, 1.1 and 1.2 down to every nested item. It is built for meeting notes, legal documents, course syllabi, technical specs, or any list that needs a clear, referenceable numbering scheme instead of loose bullets.
Choose a numbering style: arabic digits at every level for legal-style numbering (1.2.3), lowercase letters, roman numerals, or a mixed cycle that numbers the first level with digits, the second with letters and the third with roman numerals, matching the classic outline look from word processors. The separator between level segments, whether to add a trailing period after the number, the starting number, and how many spaces of indentation count as one level are all configurable, so the result matches whatever convention your document already uses.
Windows (CRLF) and Unix (LF) line endings are handled the same way, and depth is detected from leading spaces or tabs regardless of which one your outline uses — a tab always counts as one full indent level. Choose whether to renumber lines that already carry old numbers, stripping them first, or simply add fresh numbers in front of the existing text. Turn on reverse mode to strip numbering back out of an outline you already numbered. The tally under the output reports how many lines were numbered, how many levels deep the outline goes, and the total character count.
Everything runs locally in your browser — your outline is never uploaded to a server. Copy the numbered result, download it as a .txt file, or send it straight into another tool's input to keep working on it.
FAQ
How does the tool know how deep each item is nested?
It measures the leading spaces or tabs on each line. The "spaces per indent level" option sets how many spaces count as one level, and a tab always counts as one full level regardless of that setting.
What's the difference between renumbering and just adding numbers?
Renumber mode strips any number or letter already at the start of a line before adding a fresh one. Turn it off and the tool keeps the existing text exactly as it is and simply prepends the new number in front of it.
What does the "mixed" style number with?
It cycles digits, then lowercase letters, then lowercase roman numerals by depth, so a three-level outline reads 1, a, i — the classic multilevel style used in word processors.
Can I go back to a plain, unnumbered outline?
Yes. Turn on "Remove numbering instead" and the tool detects and removes existing outline numbers, leaving the indentation and text untouched.
Is my outline uploaded anywhere?
No. Outline numbering runs entirely in your browser — your text never leaves your device.