Join & Split Lines — Comma Separator Tool

Convert lines to a comma-separated list

Copying a column from a spreadsheet, a list of IDs from a report or a set of email addresses usually gives you one item per line. Many places need the opposite: a single line separated by commas. This comma separator tool converts a list of lines into a delimited string in one step. Choose a comma, comma and space, semicolon, tab, pipe, space or any custom separator, and the output updates as you type. Leading and trailing spaces are trimmed and empty lines are skipped by default, so a messy paste still produces a clean list.

For developers and analysts, two options save extra editing. Quotes wrap every item in double or single quotes, escaping any quotes inside the values. "Wrap in" adds brackets around the whole list. Together they turn a column of values into a SQL IN ('a', 'b', 'c') clause, a JavaScript or Python array like ["a", "b", "c"], or a JSON-style set in seconds. Tick "Remove duplicates" to keep only unique items.

Split a delimited list into lines

Switch the direction to turn a comma-separated (or semicolon-, tab- or pipe-separated) list back into one item per line. This is handy for reading long lists of tags, keywords, IDs or recipients, for pasting them into a spreadsheet column, or for feeding them into other line tools such as sort, deduplicate or filter. Surrounding quotes can be removed automatically, and outer brackets around the whole list are dropped. With trimming enabled, a comma-and-space delimiter also splits values that were separated by a bare comma.

The "Use output as input" button swaps the result into the input box and flips the direction, so you can round-trip a list and check that nothing was lost.

Fast and private

All conversions run in your browser, so customer lists, internal IDs and email addresses are never uploaded. There is no size limit beyond what your browser can handle comfortably.