What regex syntax does this understand?

Standard JavaScript regex syntax: character classes (\d, \w, \s and their negations), the wildcard (.), anchors (^ and $), character sets ([a-z]), capturing/non-capturing/named groups, lookaheads and lookbehinds, alternation (|), and quantifiers (*, +, ?, {n,m}, including lazy variants).

How are quantifiers attached to their explanation?

A quantifier always applies to whatever came immediately before it, so the explainer folds it into the previous token's description — for example \d+ is shown as one entry: "matches any digit, repeated one or more times" — instead of two separate unexplained pieces.

Why does it also validate the pattern?

Before explaining anything, the pattern is compiled as a real JavaScript RegExp — if it's invalid, you get the browser's own syntax error instead of a confusing or wrong breakdown.

Is my regex sent anywhere?

No. Everything runs locally in your browser with JavaScript — nothing is transmitted or stored.

REGEX EXPLAINER

Break any regular expression into a plain-English, token by token explanation. Nothing leaves your browser.

Regular expression

Highlighted pattern

^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}$

^matches the start of the string (or line, in multiline mode)

[A-Za-z0-9._%+-]+matches any character in the set [A-Za-z0-9._%+-], repeated one or more times

@matches the literal text "@"

[A-Za-z0-9.-]+matches any character in the set [A-Za-z0-9.-], repeated one or more times

\.matches an escaped literal "."

[A-Za-z]matches any character in the set [A-Za-z]

{matches the literal text "{"

2,matches the literal text "2,"

}matches the literal text "}"

$matches the end of the string (or line, in multiline mode)

Example matches

1@GrxECG.YtCzP
EE%Hu8g@PU7.Rc.TqyrGxd
eULw6Ej@JSP8.zXbfDmBS
5b+t@uh.JmsmP
m@ayq-eB.KrqWpBS

How to use the regex explainer

1
Paste a regular expression pattern.
2
The explainer breaks it into tokens — literals, character classes, groups, anchors, and quantifiers.
3
Read each token's plain-English meaning, in the order it appears in the pattern.
4
Adjust the pattern and watch the explanation update instantly.

Questions

What regex syntax does this understand?: Standard JavaScript regex syntax: character classes (\d, \w, \s and their negations), the wildcard (.), anchors (^ and $), character sets ([a-z]), capturing/non-capturing/named groups, lookaheads and lookbehinds, alternation (|), and quantifiers (*, +, ?, {n,m}, including lazy variants).
How are quantifiers attached to their explanation?: A quantifier always applies to whatever came immediately before it, so the explainer folds it into the previous token's description — for example \d+ is shown as one entry: "matches any digit, repeated one or more times" — instead of two separate unexplained pieces.
Why does it also validate the pattern?: Before explaining anything, the pattern is compiled as a real JavaScript RegExp — if it's invalid, you get the browser's own syntax error instead of a confusing or wrong breakdown.
Is my regex sent anywhere?: No. Everything runs locally in your browser with JavaScript — nothing is transmitted or stored.