Replace Spaces with Underscores
Paste bounded text and convert its ordinary ASCII spaces to underscores locally in your browser.
A QUICK WALKTHROUGH
How to use this tool
- Enter up to 100,000 UTF-16 code units.
- Replace each ASCII U+0020 space with U+005F underscore.
- Review or copy the result; line breaks and other whitespace stay unchanged.
ASCII spaces only
The tool replaces U+0020 (ordinary space) with U+005F (_). Tabs, non-breaking spaces, other Unicode whitespace, punctuation, and letters are preserved.
Bounded local processing
Input is limited to 100,000 UTF-16 code units. Processing and copying stay in this browser; text is not uploaded or stored.
GOOD TO KNOW
Common questions
Are tabs or line breaks replaced?
No. Only U+0020 ASCII spaces are replaced; tabs and all line breaks remain unchanged.
Are multiple spaces handled?
Yes. Every ASCII space is replaced individually, so repeated spaces become repeated underscores.