Regex Tester
Guide: how to use
Step-by-step instructions in the blog
Regex Tester
Test your regular expressions in real-time with syntax highlighting and a cheatsheet. CyberTools browser utility — no install.
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Results
Match
Capture Groups
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No matches found.
Try adjusting your regex pattern or test string.
Regex Cheatsheet
. | Any character except newline |
\w | Word (A-Z, a-z, 0-9, _) |
\d | Digit (0-9) |
\s | Whitespace (space, tab, etc) |
[abc] | Any of a, b, or c |
[^abc] | Not a, b, or c |
* | 0 or more |
+ | 1 or more |
? | 0 or 1 |
{3} | Exactly 3 |
{3,} | 3 or more |
{3,5} | Between 3 and 5 |
^ | Start of string / line |
$ | End of string / line |
\b | Word boundary |
(abc) | Capture group |
(?:abc) | Non-capturing group |
(?=abc) | Positive lookahead |
(?!abc) | Negative lookahead |
g | Global match |
i | Case-insensitive |
m | Multi-line |
u | Unicode |
s | Dot matches newline |
A powerful tool for developers to test and debug regular expressions. Features real-time matching, group capture visualization, syntax error reporting, and a comprehensive regex cheatsheet.
FAQ
What does Regex Tester do?
Test your regular expressions in real-time with syntax highlighting and a cheatsheet. CyberTools browser utility — no install.
Is Regex Tester free?
Regex Tester runs free in the browser on CyberTools for typical one-off tasks — no install required.
Where is the how-to guide for Regex Tester?
Open the guide — step-by-step help on the blog; this page is the interactive UI.
More tools in Developer & Data Tools?
Developer & Data Tools — open the category hub for sibling free tools in the same group.
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