/
re
\.
n
/
Privacy
GNU grep Regex Tester
Language
JavaScript
Python
Python (regex)
Java
.NET (C#)
PCRE1 (C)
PHP (PCRE2)
Go
RE2 (C++)
Rust
Rust (fancy-regex)
Ruby
Perl
POSIX (C, musl)
GNU grep -E (C)
ICU (Swift, Android)
Vim
Lua patterns
Local
, Runs in your browser
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, Runs on the server
Cloud
Local
Download
Copy
Pattern
Code
Show code
Pattern
/
/
Flags
g
, Global, every match
i
, Ignore case
m
, Line by line, as grep: ^ $ at lines, . and [^…] skip newlines
s
, Dot matches newline
x
, Verbose
U
, Ungreedy
u
, Unicode
y
, Sticky
a
, ASCII only
n
, Explicit capture
v
, Version 1 behaviour
b
, Basic syntax (grep, sed) instead of grep -E
w
, Unicode word boundaries
Test text 1
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ReDoS
Cloud
, Runs on the server
Idle
via recheck
Options
Checker
Auto
Automaton
Fuzz
Timeout
ms
Acceleration
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Seeder
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Dynamic
Advanced
Time limits
Attack
ms
Incubation
ms
Dynamic seeding
ms
Recall validation
ms
Read limits
Attack
chars
Incubation
chars
Dynamic seeding
chars
Recall validation
chars
String sizes
Attack string
chars
Gene string
chars
Recall string
chars
Fuzzing
Iterations
Initial generation
Generation
Crossovers
Mutations
Max degree
Simple repeat count
Choosing the checker
Pattern size
chars
NFA size
Repeat count
Other
Heat ratio
Random seed
Reset to defaults