How do I replace every match?

Include g in the flags. JavaScript string replacement without g replaces the first match only. Case-insensitive replacement uses i as well.

What happens when there is no match?

The output remains the original text and the replacement count is zero. An empty replacement removes matching text; it does not mean no operation.

Does this replace text in a file or editor?

It previews pasted text in your browser. It does not modify a filesystem, editor project, database or another application.

Regex Find and Replace

Switch to Replace to preview a native JavaScript replacement on your sample text. The opening example replaces both colour words with color using g. Remove g to replace only the first occurrence. Edit the pattern, flags, replacement or text and copy the current output; obsolete results cannot be copied while another run is pending.

Replacement text

$& keeps the match, $1 to $99 keep numbered groups, $<name> keeps a named group, and $$ inserts a dollar sign. Type an actual newline for a line break. Without g only the first match is replaced.

pattern/gtext16 characters

matchesmatching

Matching.

Replaced text

Replacing.

Matches: -

Groups: -

Flags

Engine: JavaScript

Matching.

d record where each match starts and ends · g find every match, not only the first · i ignore upper and lower case · m ^ and $ match at every line · s a dot also matches a newline · u read the text as unicode code points · v unicode sets, with set operations in classes · y match only where the last one left off

Two matchesglobal flag
both, with offsets
Named groups(?<user>\w+)
listed by name
Runaway patterncatastrophic backtracking
stopped by timeout

Accuracy. Matching uses your browser's own JavaScript regular expression engine, so what you see here is what your code will do. It runs in a disposable worker with a timeout, so a pattern that would hang the page is stopped and reported instead.

Common questions

How do I replace every match?: Include g in the flags. JavaScript string replacement without g replaces the first match only. Case-insensitive replacement uses i as well.
What happens when there is no match?: The output remains the original text and the replacement count is zero. An empty replacement removes matching text; it does not mean no operation.
Does this replace text in a file or editor?: It previews pasted text in your browser. It does not modify a filesystem, editor project, database or another application.

Matching uses your browser's own JavaScript regular expression engine, so what you see here is what your code will do. It runs in a disposable worker with a timeout, so a pattern that would hang the page is stopped and reported instead.