The Join Lines tool is a free online utility that merges a multi-line block of text into a single line, placing your chosen separator between each item. It turns a vertical list into one continuous string, which is exactly what you need when a form, query or code snippet expects comma-separated or space-separated values.
It is ideal for developers building lists for code, analysts creating comma-separated values from a column, and anyone converting a stacked list into an inline sentence. Rather than deleting line breaks one at a time, you paste the whole list and get a perfectly delimited single line instantly.
Everything runs inside your browser using JavaScript. The tool splits your text on line breaks, optionally trims and filters the lines, then joins them with your separator. No text is uploaded, so your lists and data remain private on your own device throughout the process.
Features of Join Lines
- Merges every line into one, inserting your chosen separator between each item.
- Custom separator supports plain text plus escapes for tab, newline and space so you can join any way you like.
- An option skips empty lines so blank rows do not create doubled or trailing separators.
- An option trims whitespace from each line before joining for a clean, consistent result.
- Line splitting recognises Windows CRLF, classic Mac CR and Unix LF endings for consistent results.
- Live statistics show how many lines were joined and the total character count of the output.
- Runs fully offline in your browser with no sign-up, no upload and no limit on input size.
How to use Join Lines
- Paste your list or multi-line text into the input box, or upload a plain text file to load it.
- Type the separator you want between items, such as a comma and space, a pipe, or a literal tab.
- Keep skip-empty enabled so blank lines do not add extra separators to the joined result.
- Enable trim if you want leading and trailing spaces removed from each line before joining.
- Copy the single-line result with one click or download it as a plain text file for your next step.
Benefits of Join Lines
- Developers turn a column of values into a comma-separated list ready to paste into code or a query.
- Analysts convert a stacked list of IDs or emails into an inline, delimited string for a single field.
- Writers collapse a bulleted list into a flowing sentence separated by commas or semicolons.
- Data workers build ready-to-use CSV rows or tag lists from a vertical column of items.
- Anyone filling a form or search box that expects delimited values saves time joining lines instantly.
Choosing the right separator matters for the destination. A comma and space suits human-readable lists, a plain comma suits CSV fields, a pipe or semicolon suits many import formats, and a tab suits pasting into spreadsheets. The separator field understands escape sequences, so you can type a tab or newline separator without leaving your keyboard.
Skipping empty lines is usually what you want, because a blank line between items would otherwise produce two separators in a row or a stray separator at the end. With skip-empty enabled the tool only joins lines that contain content, giving you a clean delimited string with no gaps, which is important when the result feeds a parser or code.