Comma Separator – List Formatter Online
Comma Separator Convert vertical lists to comma-separated strings - or reverse - with quote wrapping, dedupe, sort, and SQL-ready prefix/suffix. Free, client-side.
Turn a vertical list into a single-line comma-separated string — or reverse — with quote wrapping, dedupe, sort, and optional SQL-ready prefix/suffix.
How to Use Comma Separator – List Formatter Online
- Paste your list into the left textarea - one item per line when going vertical → inline, or a single delimited string when going inline → vertical. The output repaints automatically after each keystroke (debounced by 200 ms).
- Pick the direction from the first dropdown: Vertical → Inline (the default, for turning a spreadsheet column into one line) or Inline → Vertical (for splitting a comma string back into rows).
- Choose a delimiter: Comma + space is the most common, strict Comma is compact CSV-style, Pipe is common for shell and database tools, Semicolon + space fits European locales, Tab is for TSV, Space and Newline cover the edge cases.
- Wrap items in quotes if the destination needs it - Single quotes for SQL
INclauses, Double quotes for JSON arrays or CSV fields, Backticks for Markdown or SQL identifiers. Choose None for plain text. - Add a prefix and suffix (optional) to surround the whole output - for example
IN (and)produce a paste-ready SQL fragment in one step. When you reverse, the same prefix/suffix is stripped before splitting. - Flip the toggles to control per-item cleanup: Trim whitespace, Remove empty lines, Deduplicate (preserving first occurrence), and Sort alphabetically (locale-aware and numeric-smart, so
item2sorts beforeitem10). - Read the stats line to verify counts and byte totals, then Copy to the clipboard, Download .txt for a timestamped file, or press
Ctrl+Enter(⌘+Enteron Mac) to force a re-run from anywhere on the page.
Frequently asked questions
Is my list data secure?
Yes. All parsing, joining, dedupe, and sort runs in your browser with vanilla JavaScript. Nothing is uploaded, cached, or tracked – you can disconnect the network and keep working.
Is this comma separator tool free?
Yes, 100% free with unlimited conversions. No sign-up, no premium tier, no watermark, no rate limit.
Does this work offline?
Yes. After the page loads, HTML/CSS/JS are self-contained. Turn off Wi-Fi and keep formatting lists indefinitely.
What is the difference between the delimiter options?
Comma + space produces readable output like apple, banana, cherry. Strict Comma is compact for CSV. Pipe is common in shell tools (apple|banana). Semicolon + space fits European CSVs. Tab is for TSV. Space and Newline are there for edge-case cleanups.
When should I wrap items in quotes?
Single quotes for SQL IN clauses like ('apple','banana'). Double quotes for JSON arrays and CSV cells that contain spaces. Backticks for SQL identifiers or Markdown inline code. Leave None for plain text.
How do I build a SQL IN clause?
Pick delimiter Strict comma, quotes Single, prefix IN (, suffix ). Paste your list and the output is ready to drop into SELECT * FROM table WHERE col IN (…) verbatim.
Does the tool remove empty lines and trim whitespace?
Yes – both toggles are on by default. Remove empty lines drops blank rows (and trailing newlines from a paste). Trim whitespace strips leading/trailing spaces per item, so "apple " and "apple" collapse to the same value before dedupe.
Can I convert a comma list back to a vertical list?
Yes – switch the Direction dropdown to Inline → Vertical. The tool respects the same Delimiter, Quote, Prefix and Suffix settings, strips matching quotes symmetrically, and writes one item per line.
How many items can I process?
There is no hard cap. Ten thousand items convert in under 50 ms on a typical laptop. Input is debounced by 200 ms so the preview never stutters even on very long pastes.
Are Unicode characters and emoji supported?
Yes. Items like café, 日本語, and 🍕 round-trip cleanly, and the stats line reports UTF-8 byte totals via TextEncoder so you know the exact payload size.