Does this add the suffix once, or to every line?

It adds the suffix to every line of the input, splitting on newlines first. For a single suffix added once to the whole text, use Suffix Adder instead.

What happens with an empty line?

Empty lines still get the suffix appended, since the tool maps over every line produced by splitting on '\n', including blank ones.

Line Suffix Adder Online - Append Text to Every Line

Overview

Introduction

Adding the same trailing character or word to every line of a list, a comma for a code array, a semicolon for a config file, is a repetitive edit that's easy to get wrong by hand.

It runs entirely client-side, so nothing you paste is ever uploaded to a server.

What Is Line Suffix Adder?

A line-based suffixing tool that appends your chosen suffix to the end of every line in the input, rather than just once at the very end of the whole text.

It runs entirely client-side as part of this site's String Tools collection, so nothing you paste is ever uploaded to a server.

How Line Suffix Adder Works

The tool splits the input on newline characters, appends the suffix to each resulting line, and joins the lines back together with newlines.

The transformation happens synchronously in JavaScript the moment you type, with no network round trip involved.

When To Use Line Suffix Adder

Use it to add a trailing comma to every line for a code array, a semicolon for a statement list, or any other consistent closing marker across many lines.

It's a fast way to get the answer without opening a code editor, a REPL, or writing a one-off script just to check.

Often used alongside Suffix Adder, Line Prefix Adder and Text Joiner.

Features

Advantages

Applies the suffix to every line in one pass, not just the end of the text.
Preserves blank lines and line order exactly.

Limitations

Adds the same fixed suffix to every line, including the last one, so a trailing comma on the final entry may need manual removal.
Does not trim or otherwise alter existing line content.

Examples

Adding trailing commas for a code array

Input

apple
banana
cherry

Output

apple,
banana,
cherry,

With suffix ',', each of the three lines gets a comma appended, including the last line.

Best Practices & Notes

Best Practices

Remember the suffix is appended to every line including the last; remove it manually from the final line if a trailing comma isn't wanted.

Developer Notes

The implementation is `input.split("\n").map((line) => line + suffix).join("\n")`, a straightforward per-line map with no trimming or filtering of the resulting lines.

Line Suffix Adder Use Cases

Adding trailing commas to build a code array or list literal
Appending a semicolon to every statement in a list
Adding a shared closing tag or marker to each line

Common Mistakes

Expecting the suffix to be added only once, at the end of the text, rather than to every line.
Forgetting the suffix also lands on the last line, which is often unwanted for a trailing comma.

Tips

Use Line Prefix Adder alongside this tool to wrap each line with both a prefix and a suffix.

Line Suffix Adder