Does it affect tabs or newlines?

No. Only the literal space character (U+0020) is replaced; tabs, newlines, and other whitespace are left as-is.

Can the replacement be empty?

Yes, an empty replacement effectively deletes every space, joining words together with nothing between them.

What happens to consecutive spaces?

Each one is replaced separately, so two spaces produce two copies of your replacement. Collapse the extras first with the Extra Space Remover when you want exactly one separator between words.

String Space Replacer - Replace Spaces With Any Character

Overview

Introduction

Turning a sentence or phrase into a slug, filename, or identifier usually starts with getting rid of literal spaces.

This tool does that in one step, and runs entirely client-side, so nothing you paste is ever uploaded to a server.

What Is String Space Replacer?

A find-and-replace tool specialized for the space character: it swaps every literal space in your text for a replacement string you choose.

It's part of this site's String Tools collection and works entirely in your browser.

How String Space Replacer Works

The tool splits the input on the space character and rejoins the pieces using your replacement string in place of each gap.

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

When To Use String Space Replacer

Use it when you need to convert a phrase into a slug-like token, such as turning 'my file name' into 'my_file_name'.

It's also handy for quickly building identifiers, tags, or filenames out of freeform text.

Often used alongside Whitespace Trimmer and Whitespace Remover.

Features

Advantages

Works with any replacement string, not just a fixed underscore.
Simple, predictable, single-character-class replacement.
Substitutes literally through a split and join, so a replacement containing regex-special characters is inserted exactly as typed.

Limitations

Only targets the literal space character; other whitespace like tabs and newlines are untouched.
Doesn't lowercase or otherwise sanitize the text, unlike a full slugify tool.

Examples

Replacing spaces with underscores

Input

my file name

Output

my_file_name

Every space is replaced with the chosen replacement string, here an underscore.

Best Practices & Notes

Best Practices

Use Slugify a String instead if you also need lowercasing and character sanitization for URLs.
Choose a replacement that won't collide with characters already in your text if the result needs to be reversible.
Collapse runs of spaces before converting, otherwise a double space yields two separators and breaks an otherwise clean identifier.

Developer Notes

The implementation is `input.split(" ").join(replacement)`, which handles any replacement string (including a multi-character one or an empty string) without regex escaping concerns.

String Space Replacer Use Cases

Converting a phrase into a slug-like token
Building a filename out of freeform text
Creating an identifier from a multi-word label

Common Mistakes

Expecting tabs or newlines to also be replaced; only literal spaces are affected.
Using this for URL slugs when full slugification (lowercasing, removing special characters) is actually needed.

Tips

Combine with a case converter afterward if you want a fully normalized slug, like lowercase with underscores.
Leaving the replacement empty removes the spaces altogether, turning a phrase into a single unbroken token.

String Space Replacer