Regular Expressions 101

Save & Manage Regex

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
Processing...

Test String

Code Generator

Language

Generated Code

$re = '/^(((?!25?[6-9]|0)[12]?\d|2)?\d\.?\b){4}$/m'; $str = '30.168.1.255.1 127.1 192.168.1.256 -1.2.3.4 1.1.1.1. .1.1.1.1 01.1.1.1 3...3 1212.1.1.1 2121.1.1.1 0.0.0.0 1.7.3.5 2.14.6.10 3.21.9.15 4.28.12.20 5.35.15.25 6.42.18.30 7.49.21.35 8.56.24.40 9.63.27.45 10.70.30.50 11.77.33.55 12.84.36.60 13.91.39.65 14.98.42.70 15.105.45.75 16.112.48.80 17.119.51.85 18.126.54.90 19.133.57.95 20.140.60.100 21.147.63.105 22.154.66.110 23.161.69.115 24.168.72.120 25.175.75.125 26.182.78.130 27.189.81.135 28.196.84.140 29.203.87.145 30.210.90.150 31.217.93.155 32.224.96.160 33.231.99.165 34.238.102.170 35.245.105.175 36.252.108.180 37.3.111.185 38.10.114.190 39.17.117.195 40.24.120.200 41.31.123.205 42.38.126.210 43.45.129.215 44.52.132.220 45.59.135.225 46.66.138.230 47.73.141.235 48.80.144.240 49.87.147.245 50.94.150.250 51.101.153.255 52.108.156.4 53.115.159.9 54.122.162.14 55.129.165.19 56.136.168.24 57.143.171.29 58.150.174.34 59.157.177.39 60.164.180.44 61.171.183.49 62.178.186.54 63.185.189.59 64.192.192.64 65.199.195.69 66.206.198.74 67.213.201.79 68.220.204.84 69.227.207.89 70.234.210.94 71.241.213.99 72.248.216.104 73.255.219.109 74.6.222.114 75.13.225.119 76.20.228.124 77.27.231.129 78.34.234.134 79.41.237.139 80.48.240.144 81.55.243.149 82.62.246.154 83.69.249.159 84.76.252.164 85.83.255.169 86.90.2.174 87.97.5.179 88.104.8.184 89.111.11.189 90.118.14.194 91.125.17.199 92.132.20.204 93.139.23.209 94.146.26.214 95.153.29.219 96.160.32.224 97.167.35.229 98.174.38.234 99.181.41.239 100.188.44.244 101.195.47.249 102.202.50.254 103.209.53.3 104.216.56.8 105.223.59.13 106.230.62.18 107.237.65.23 108.244.68.28 109.251.71.33 110.2.74.38 111.9.77.43 112.16.80.48 113.23.83.53 114.30.86.58 115.37.89.63 116.44.92.68 117.51.95.73 118.58.98.78 119.65.101.83 120.72.104.88 121.79.107.93 122.86.110.98 123.93.113.103 124.100.116.108 125.107.119.113 126.114.122.118 127.121.125.123 128.128.128.128 129.135.131.133 130.142.134.138 131.149.137.143 132.156.140.148 133.163.143.153 134.170.146.158 135.177.149.163 136.184.152.168 137.191.155.173 138.198.158.178 139.205.161.183 140.212.164.188 141.219.167.193 142.226.170.198 143.233.173.203 144.240.176.208 145.247.179.213 146.254.182.218 147.5.185.223 148.12.188.228 149.19.191.233 150.26.194.238 151.33.197.243 152.40.200.248 153.47.203.253 154.54.206.2 155.61.209.7 156.68.212.12 157.75.215.17 158.82.218.22 159.89.221.27 160.96.224.32 161.103.227.37 162.110.230.42 163.117.233.47 164.124.236.52 165.131.239.57 166.138.242.62 167.145.245.67 168.152.248.72 169.159.251.77 170.166.254.82 171.173.1.87 172.180.4.92 173.187.7.97 174.194.10.102 175.201.13.107 176.208.16.112 177.215.19.117 178.222.22.122 179.229.25.127 180.236.28.132 181.243.31.137 182.250.34.142 183.1.37.147 184.8.40.152 185.15.43.157 186.22.46.162 187.29.49.167 188.36.52.172 189.43.55.177 190.50.58.182 191.57.61.187 192.64.64.192 193.71.67.197 194.78.70.202 195.85.73.207 196.92.76.212 197.99.79.217 198.106.82.222 199.113.85.227 200.120.88.232 201.127.91.237 202.134.94.242 203.141.97.247 204.148.100.252 205.155.103.1 206.162.106.6 207.169.109.11 208.176.112.16 209.183.115.21 210.190.118.26 211.197.121.31 212.204.124.36 213.211.127.41 214.218.130.46 215.225.133.51 216.232.136.56 217.239.139.61 218.246.142.66 219.253.145.71 220.4.148.76 221.11.151.81 222.18.154.86 223.25.157.91 224.32.160.96 225.39.163.101 226.46.166.106 227.53.169.111 228.60.172.116 229.67.175.121 230.74.178.126 231.81.181.131 232.88.184.136 233.95.187.141 234.102.190.146 235.109.193.151 236.116.196.156 237.123.199.161 238.130.202.166 239.137.205.171 240.144.208.176 241.151.211.181 242.158.214.186 243.165.217.191 244.172.220.196 245.179.223.201 246.186.226.206 247.193.229.211 248.200.232.216 249.207.235.221 250.214.238.226 251.221.241.231 252.228.244.236 253.235.247.241 254.242.250.246 255.249.253.251 256.0.0.0 1.257.1.1 2.2.258.2 3.3.3.259 260.4.4.4 5.261.5.5 6.6.262.6 7.7.7.263 264.8.8.8 9.265.9.9 10.10.266.10 11.11.11.267 268.12.12.12 13.269.13.13 14.14.270.14 15.15.15.271 272.0.0.0 1.273.1.1 2.2.274.2 3.3.3.275 276.4.4.4 5.277.5.5 6.6.278.6 7.7.7.279 280.8.8.8 9.281.9.9 10.10.282.10 11.11.11.283 284.12.12.12 13.285.13.13 14.14.286.14 15.15.15.287 288.0.0.0 1.289.1.1 2.2.290.2 3.3.3.291 292.4.4.4 5.293.5.5 6.6.294.6 7.7.7.295 296.8.8.8 9.297.9.9 10.10.298.10 11.11.11.299 300.12.12.12 13.301.13.13 14.14.302.14 15.15.15.303 304.0.0.0 1.305.1.1 2.2.306.2 3.3.3.307 308.4.4.4 5.309.5.5 6.6.310.6 7.7.7.311 312.8.8.8 9.313.9.9 10.10.314.10 11.11.11.315 316.12.12.12 13.317.13.13 14.14.318.14 15.15.15.319'; preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0); // Print the entire match result var_dump($matches);

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php