Joining Text: Turning a List Into One String

A column of values is the easiest thing in the world to produce and one of the hardest to use. Spreadsheets, log files, and copy-pasted lists all hand you data one item per line — but CSV rows, SQL queries, tag strings, and URLs want everything on one line, with a character between each pair. The bridge between those two worlds is the join: split into items, clean each one, and glue them back together with a separator. It is the inverse of splitting, and it is where most copy-paste chores actually end.

Split, clean, join

Every join starts with a split. A text joiner offers two views of the same input: split on line breaks, so each line becomes one item, or split on whitespace, so each word becomes one item. Then comes the quiet, load-bearing step — every item is trimmed of surrounding whitespace and empty items are dropped. That step is what makes the tool forgiving: paste a list with trailing spaces, blank lines in the middle, or a stray tab, and none of it leaks into the output.

input (lines):      input (words):
  apple             one two  three
  banana
  apple

items: ['apple',     items: ['one', 'two', 'three']
        'banana',
        'apple']

The word view is stricter about what an item is — any whitespace run is a boundary, so one two  three is three items, not two. The line view respects your line structure and only trims the edges. Choosing between them is choosing what a "value" means in your data.

The separator does the real work

The separator is the personality of the output. A comma followed by space turns a list into readable prose; a bare comma makes CSV; a semicolon with space suits prose lists that already contain commas; a pipe or dash makes human-skimmable tables; a space produces a tag string; a newline splits — in effect re-formatting the list with a different rhythm. Built-in presets cover the common cases, and a custom field accepts anything, including multi-character separators like | or a literal newline.

['apple', 'banana', 'apple']
join ', '    -> apple, banana, apple
join ','     -> apple,banana,apple
join ' '     -> apple banana apple

One boundary worth knowing: the tool inserts the separator between items and nothing else. It does not wrap items in quotes or brackets. If you need 'apple','banana','apple' for a SQL IN clause, join with a comma first and then add the quotes — the Find and Replace Text tool does that in one pass.

Dedupe before you join

Lists assembled by hand or by copy-paste accumulate duplicates, and a joined string inherits every one of them. The remove-duplicates option keeps only the first occurrence of each item, preserving original order — which matters when the order is meaningful:

apple / banana / apple
dedupe off -> apple, banana, apple   (3 items)
dedupe on  -> apple, banana          (2 items)

Deduplication happens during the join, not as a separate pass, which is convenient — but it is a different job from the Remove Duplicate Lines tool, which strips repeats while keeping your line structure intact. If the output should still be a multi-line list, use that tool; if the output should be one string, dedupe here.

Where joins end up

The joined string is rarely the destination; it is the format some other system demanded. Turning a spreadsheet column into a CSV row. Building tag1,tag2,tag3 for a form field or a URL parameter. Assembling a single-line summary from meeting notes. Producing the comma-separated value list that a query or a config file wants. In each case the mental model is the same — items, separator, and optionally a dedupe — and once you see the model, the tool is a two-click affair. The sibling operations live nearby: sorting the items first with the Line Sorter, or the whole split-sort-join pipeline described in Find & Replace, Line Sorting, and Joining Text.

Try it yourself

Paste apple / banana / apple (one per line) into the Text Joiner and join with , to get a clean three-item string. Toggle remove-duplicates and watch it become two. Then switch the split mode from lines to words, type a custom separator like | , and see how the same input produces a completely different shape of output.