Can I search for a specific concept?

Yes, search by pattern, description, example, or category.

Are the examples runnable?

They're illustrative text examples; use the Regex Tester tool to try patterns live.

Can I copy a pattern?

Yes, click the copy button next to any pattern.

Is my data uploaded to a server?

No. This tool runs entirely in your browser using standard web APIs, so your input never leaves your device and nothing is logged or stored on our servers.

Does it work offline and on mobile?

Yes. Once the page has loaded it keeps working without a network connection, and the layout is responsive so it stays usable on phones and tablets.

Regex Cheatsheet

Searchable regex syntax reference with examples and copy buttons.

Support

Works Offline

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No API

Search patterns

Basics

.
Any character except newline
a.c matches abc

Character classes

\d
Any digit (0-9)
\d+ matches 123
\D
Any non-digit
\D+ matches abc
\w
Word character (letter, digit, underscore)
\w+ matches hello_1
\W
Non-word character
\W matches !
\s
Whitespace character
a\sb matches 'a b'
\S
Non-whitespace character
\S+ matches abc
[abc]
Any of a, b, or c
[abc]+ matches cab
[^abc]
Any character except a, b, c
[^abc] matches d
[a-z]
Any lowercase letter
[a-z]+ matches hello

Anchors

^
Start of string/line
^Hello matches 'Hello world'
$
End of string/line
world$ matches 'Hello world'
\b
Word boundary
\bcat\b matches 'a cat sat'
\B
Non-word boundary
\Bcat matches 'concatenate'

Quantifiers

*
0 or more of the previous token
ab*c matches ac, abc, abbc
+
1 or more of the previous token
ab+c matches abc, abbc
?
0 or 1 of the previous token (optional)
colou?r matches color, colour
{n}
Exactly n repetitions
\d{3} matches 123
{n,}
n or more repetitions
\d{2,} matches 12, 123
{n,m}
Between n and m repetitions
\d{2,4} matches 12, 123, 1234
*?
Lazy (non-greedy) 0 or more
<.*?> matches '<a>' first, not '<a><b>'

Groups

(abc)
Capturing group
(ab)+ captures repeated 'ab'
(?:abc)
Non-capturing group
(?:ab)+ groups without capturing
(?<name>abc)
Named capturing group
(?<year>\d{4})
a|b
Alternation — a or b
cat|dog matches cat or dog

Lookaround

(?=abc)
Positive lookahead
\d(?=px) matches digit before 'px'
(?!abc)
Negative lookahead
\d(?!px) matches digit not before 'px'
(?<=abc)
Positive lookbehind
(?<=\$)\d+ matches digits after $
(?<!abc)
Negative lookbehind
(?<!\$)\d+ matches digits not after $

Flags

g
Global flag — find all matches
/a/g
i
Case-insensitive flag
/abc/i matches ABC
m
Multiline flag — ^ and $ match line boundaries
/^a/m
s
Dotall flag — . matches newlines too
/a.b/s
u
Unicode flag
/\u{1F600}/u

Basics

Character classes

Anchors

Quantifiers

Groups

Lookaround

Flags

About the Regex Cheatsheet

Browse a categorized, searchable reference of regular expression syntax — character classes, anchors, quantifiers, groups, lookaround, and flags — each with an example and a copy button.

Examples

Lookahead

lookahead

Output

(?=abc) — positive lookahead

Keyboard shortcuts

Copy the main outputCtrl / ⌘ + Shift + C
Download the resultCtrl / ⌘ + S
Share this toolCtrl / ⌘ + Shift + S
Reset the inputsAlt + R
Open the tool search paletteCtrl / ⌘ + K

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Version 1.0.0 · Updated 2026-08-06 · Runs entirely in your browser

Regex Cheatsheet

About the Regex Cheatsheet

Examples

Keyboard shortcuts

Related tools

Regex Tester

Code Comment Stripper

Code Screenshot Generator

Line Sorter & Deduper

Markdown TOC Generator

String Escaper

Frequently asked questions

Can I search for a specific concept?

Are the examples runnable?

Can I copy a pattern?

Is my data uploaded to a server?

Does it work offline and on mobile?

Read more