How to join multiple lines into one line

The short answer. Paste your lines into the line joiner, type a separator (default , ), copy the one-line result. In Excel, =TEXTJOIN(", ", TRUE, A1:A100). In Word, Find & Replace ^p with the separator. In Notepad++, switch Replace to Extended mode and replace \r\n or \n with your string. On the command line, paste -sd, file.txt joins all lines with a comma. The choice between them comes down to where the lines already live.

When do you need to join lines into one?

Four common cases cover most of the real-world need:

• SQL IN() lists. You have a column of IDs, you need (1, 2, 3, ...) for a query.
• CSV-style cells. A list of tags or categories that needs to fit into one cell, separated by commas or semicolons.
• HTML / Markdown attributes. Comma-separated class lists, space-separated keywords, slug-style joins.
• Reflowing wrapped text. Pasted from a PDF or email where the lines broke at column 72; you want one paragraph back. (For this case, the line break remover with the "space" replacement is a closer fit than a true join.)

The trick is picking a separator that's not already in your data. If any of your items already contain a comma, ", " as a separator gives you an ambiguous output. Pick a pipe (|), a tab, or a more unusual character when collisions matter.

How do you join lines online, instantly?

Open the line joiner. Paste your list, type a separator in the input box, copy the result.

• Default separator is ", " — the most common case (SQL IN() lists, comma-separated tags). Override with any string: |, ;, — , a tab character, your own slug.
• Newline as a separator. Type \n literally in the box to get a multi-line result back — useful when you're switching between joiners for an intermediate step.
• Blanks skipped by default. Empty rows are dropped before joining, so you don't get ", , , " messes. Toggle Skip blanks off to keep them as empty items.
• Trim each line by default. Leading and trailing whitespace per line gets removed before joining. Toggle off if your data has meaningful indentation.
• Nothing uploads. The whole join is a single Array.join() call in the browser. Open DevTools → Network to verify — zero outbound requests carrying your list.

How do you join lines in Excel?

Three good options depending on Excel version and your separator preference.

TEXTJOIN (Excel 2019, 365, 2021).

=TEXTJOIN(", ", TRUE, A1:A100)

First argument is the separator. Second (TRUE) means "skip blanks" — the most common preference. Third is the range. This is by far the cleanest join in modern Excel.

CONCAT (Excel 2019+, no separator).

=CONCAT(A1:A100)

Glues the cells together with nothing between. Useful when your cells already contain their own delimiters or when you want a pure concatenation.

The older & operator for tiny lists:

=A1 & ", " & A2 & ", " & A3

Doesn't scale beyond a handful of cells. For anything larger, TEXTJOIN wins.

To wrap the result in parentheses for a SQL IN() clause, nest it:

="(" & TEXTJOIN(", ", TRUE, A1:A100) & ")"

How do you join lines in Google Sheets?

Identical to modern Excel. TEXTJOIN and JOIN both work:

=TEXTJOIN(", ", TRUE, A1:A100)
=JOIN(", ", A1:A100)

The Sheets-specific JOIN is shorter but doesn't have a blank-skipping argument; TEXTJOIN with TRUE as the second argument is the safer default. For SQL-friendly output:

="(" & TEXTJOIN(", ", TRUE, A1:A100) & ")"

How do you join lines in Microsoft Word?

Word's Find & Replace can collapse a list into one line.

1. Press Ctrl+H.
2. In Find what, type ^p (paragraph mark) or ^l (manual line break, from Shift+Enter) depending on what you have.
3. In Replace with, type your separator: , , ; , |, whatever you want.
4. Click Replace All.

Two gotchas: (a) you'll end up with a trailing separator on the last line — clean it up manually. (b) If Track Changes is on, paragraph marks won't replace; turn it off first.

How do you join lines in Notepad++ or VS Code?

Text editors handle joins faster than Word for plain-text input.

Notepad++

1. Press Ctrl+H.
2. Set Search Mode to Extended.
3. In Find what: \r\n (Windows) or \n (Unix); use Regular expression mode with \r?\n to cover both.
4. In Replace with, type your separator.
5. Click Replace All.

VS Code

1. Select all lines (Ctrl+A).
2. Press Ctrl+J (Windows / Linux) or Cmd+J (macOS) — this is the built-in Join Lines command. It joins selected lines with a single space.
3. If you need a different separator, use Find & Replace instead: Ctrl+H, enable regex, search \r?\n, replace with your string.

How do you join lines on the command line?

Three quick recipes.

paste with a separator — the right tool when one exists:

paste -sd, file.txt

Joins every line in file.txt with a comma. -s means "serial" (concat into one line), -d sets the delimiter. paste only takes a single-character delimiter — for ", " (comma + space) or anything longer, jump to the sed recipe below.

tr for newline-to-anything joins:

tr '\n' ',' < file.txt

Single-character delimiter only.

sed for full-power joins:

sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/, /g' file.txt

The cryptic preamble reads the whole file into one buffer first; the substitution then replaces every newline with ", ". Same recipe as the line-break-removal article — same reason needed.

On Windows in PowerShell:

(Get-Content file.txt) -join ", "

Cleaner than the Unix versions, no buffer dance required.

Which method should you use?

Frequently asked questions

How do I avoid a trailing separator?

Most well-designed tools put separators only between items, not after the last one. The browser tool, TEXTJOIN, paste, and PowerShell's -join all do this correctly. The Word Find & Replace approach is the exception — it replaces every paragraph mark, including the last one, so you'll end up with a trailing comma. Delete it manually.

What if my data already contains commas?

Pick a different separator. Pipes (|), tabs (\t), or unusual characters like — avoid collisions. For SQL or CSV output where commas are expected, you usually need to quote each item first — for example, =TEXTJOIN(", ", TRUE, "'" & A1:A100 & "'") to wrap each value in single quotes.

How do I join lines but keep paragraph breaks?

Treat single newlines and double newlines differently. The line break remover with the Keep paragraphs toggle is the cleanest path — single breaks collapse to your separator, double breaks (blank lines between paragraphs) stay intact. Pure join tools collapse everything; this is closer to "reflow".

Can I join lines into a JSON array?

Yes, but it's two steps. (1) Wrap each line in quotes — use the prefix tool with prefix " and the suffix tool with suffix ". (2) Join with , . (3) Wrap the whole thing in [ ]. Or just write a one-liner in your language of choice — for one-off output the manual approach is usually faster than firing up a script.

What's the fastest way for a 100,000-line list?

Command line or PowerShell -join. Both finish near-instantly because they're working in memory without any UI overhead. Excel's TEXTJOIN can struggle past about 30,000 cells depending on the per-cell length — if the resulting string is too large for a cell (the 32,767-character limit), Excel returns #VALUE!. The browser tool handles large lists fine in principle, but the clipboard paste step becomes the bottleneck above a certain size before the tool does.

Is it safe to paste sensitive lines into an online joiner?

Only if the tool runs entirely in the browser. Open DevTools → Network, paste your list, do a join, and watch for outbound requests. If anything carries your data, the page sent it to a server. The joinlines joiner makes zero requests after page load — verifiable in DevTools.

— the joinlines team, 2026-04-15