Overview
Introduction
Appending a fixed suffix to text, a file extension, a unit, closing punctuation, is a one-line operation in code but convenient to have as a standalone tool.
It runs entirely client-side, so nothing you paste is ever uploaded to a server.
What Is Suffix Adder?
A suffixing tool that concatenates your chosen suffix onto the end of the input 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 Suffix Adder Works
The tool simply returns `input + suffix`.
The transformation happens synchronously in JavaScript the moment you type, with no network round trip involved.
When To Use Suffix Adder
Use it to quickly append a file extension, a unit of measure, or trailing punctuation to a value.
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 Prefix Adder and Find & Replace Tool.
Features
Advantages
- Simple and predictable, a direct string concatenation.
Limitations
- Adds the suffix once to the whole input, not per line.
Examples
Best Practices & Notes
Best Practices
- For per-line suffixing across multiple lines, process each line individually.
Developer Notes
The implementation is a single string concatenation (`input + suffix`), with no per-line splitting.
Suffix Adder Use Cases
- Appending a file extension to a filename
- Adding a unit of measure to a numeric value
- Appending closing punctuation to a sentence
Common Mistakes
- Expecting the suffix to be added to every line of multi-line input.
Tips
- Use Add a Prefix to a String for the equivalent operation at the front of the text.