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正则表达式测试器

测试正则表达式

在浏览器中运行 · 无需上传

此工具及本页说明目前仍为英文。功能完全相同：一切都在你的浏览器中运行。

Flags
Matches in the text
Use $1, $2… for groups, $<name> for named groups and $& for the whole match.
As JavaScript: /…/g
Quick reference
WriteMatches
.any character except a line break
\d \w \sa digit, a word character (letter, digit, _), a space
\D \W \Sanything but those
[abc] [^abc] [a-z]one of, none of, a range
^ $start and end of the text (or of each line with m)
\ba word boundary
a* a+ a?0 or more, 1 or more, 0 or 1
a{3} a{2,5} a{2,}exactly 3, 2 to 5, 2 or more
a*? a+?as few as possible (lazy)
(abc) (?<name>abc)a group, a named group
(?:abc)a group that isn't captured
a|ba or b
(?=a) (?!a)followed by a, not followed by a
(?<=a) (?<!a)preceded by a, not preceded by a
\. \* \(a literal . * ( (escape special characters with \)

This tester uses your browser's own JavaScript engine, so it behaves exactly like regular expressions in JavaScript. Other languages (PCRE, Python, Java) differ in some details.

  • 任何内容都不会离开你的设备
  • 服务器不限制文件大小
  • 无需注册，无水印
  • 免费

How to test a regular expression

  1. Type the pattern between the slashes and choose flags such as g (all matches) or i (ignore case).
  2. Paste the text to search. Matches are highlighted as you type.
  3. Check the groups in the table, and try a replacement such as $1 or $<name>.

Safe to experiment

Each pattern runs with a two-second time limit, so a pattern that never finishes (catastrophic backtracking, such as (a+)+$) is stopped instead of freezing the page.

Which flavour?

This is your browser's JavaScript engine, so results are exactly what JavaScript code will do. PCRE (PHP), Python and Java mostly agree but differ in details such as lookbehind support, Unicode classes and replacement syntax.

常见问题

Why does my pattern only find one match?

Turn on the g flag to find every match; without it, only the first is found.

Is my text uploaded?

No. Everything happens in your browser, and the page is blocked from uploading anything.