How do I keep spaces?

Add a literal space inside the negated character class: [^A-Za-z0-9 ] keeps ASCII letters, digits and ordinary spaces. It still removes tabs, line breaks and non-ASCII letters.

Can I preserve Unicode letters and numbers?

Use [^\p{L}\p{N}] with gu in a browser supporting Unicode property escapes. This keeps Unicode letters and numbers; combining marks require an additional \p{M} if your rule needs them.

Does stripping HTML tags sanitize HTML?

No. Regex character removal is not an HTML parser or a sanitizer. Nested markup, quoted attributes and unsafe content need a dedicated HTML workflow.

Remove Characters with a Regex

This workflow opens [^A-Za-z0-9] with g and an empty replacement: Order #A-42! becomes OrderA42. The example removes spaces and all non-ASCII letters as well as punctuation, so change the rule to match what you intend to keep. Use \s+ and a single space to collapse whitespace, or a narrower character class to remove only specified symbols.

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/gtext12 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 keep spaces?: Add a literal space inside the negated character class: [^A-Za-z0-9 ] keeps ASCII letters, digits and ordinary spaces. It still removes tabs, line breaks and non-ASCII letters.
Can I preserve Unicode letters and numbers?: Use [^\p{L}\p{N}] with gu in a browser supporting Unicode property escapes. This keeps Unicode letters and numbers; combining marks require an additional \p{M} if your rule needs them.
Does stripping HTML tags sanitize HTML?: No. Regex character removal is not an HTML parser or a sanitizer. Nested markup, quoted attributes and unsafe content need a dedicated HTML workflow.

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.