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Add Prefix
Put the same text at the start of every line.
Use {n} to insert the line number.
Quick Tool Overview
Add Prefix puts the same text at the start of every line in a list — a domain in front of paths, a hyphen to make Markdown bullets, a comment marker in front of code. Blank lines are skipped and existing indentation can be preserved.
- What it does
- Adds text to the start of every line
- You give it
- A list, one item per line
- You get back
- The list with your prefix on every line
- Best for
- Prepending domains, markers, codes and bullets
About the Add Prefix
Adding the same thing to the front of every line is one of the most common list operations there is. A domain in front of a list of paths. A hyphen in front of a list of items to make it Markdown. A comment marker in front of a block of code. A country code in front of a column of phone numbers.
Doing it by hand means clicking to the start of each line and typing, which is fine for five lines and unbearable for five hundred. This does the whole list at once. Blank lines can be skipped, existing indentation can be preserved so the prefix goes after it rather than before, and a {n} placeholder is replaced with the line number for numbered output.
Key features of the Add Prefix
Indentation preserved
Place the prefix after existing whitespace so nested structure survives — what commenting out indented code needs.
Blank lines skipped
No line consisting only of the prefix, unless you explicitly want every line treated the same.
The {n} placeholder
Insert the line number in the prefix for quick numbered output.
Whole list at once
Five hundred lines take the same single action as five.
Download the result
Save the prefixed list straight to a file rather than copying it in pieces.
How to use the Add Prefix
-
1
Paste your list
One item per line — paths, names, numbers or code.
-
2
Type the prefix
The text to add at the start of every line. Use {n} to insert the line number.
-
3
Handle indentation
Place the prefix at the very start, or after any existing indentation so nested structure survives.
-
4
Copy the result
Copy or download the prefixed list.
Frequently asked questions
Not by default. Blank lines are skipped, since a line containing only the prefix is almost never intended. There is a switch to include them when you need every line treated the same.
You choose. Placing the prefix at the very start puts it before the indentation; placing it after preserves the nesting, which is what you want when commenting out indented code.
Yes, put {n} in the prefix. For anything more than a simple counter — padding, a custom step, continuing from a previous section — Add Line Numbers is the better tool.
Use Prefix & Suffix Text, which does both ends in one pass and adds the separator and wrapping that data formats need.
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