I wanted to validate only for IP address accepting only 3 three dots after some numbers

ex: Valid: 191.123.121.202 is valid which has 3 dots after some decimal. Invalid : 191..123.121.202 is invalid where 2 dots are in sequence

Whole Point: wanted a robust IP validator

$("input.onlynumberdecimal").keydown(function (event) {

        console.log(event.keyCode);

        if (event.shiftKey == true) {
            event.preventDefault();
        }

        if ((event.keyCode >= 48 && event.keyCode <= 57) || 
            (event.keyCode >= 96 && event.keyCode <= 105) || 
            event.keyCode == 8 || event.keyCode == 9 || event.keyCode == 37 ||
            event.keyCode == 39 || event.keyCode == 46 || event.keyCode == 190) {

        } else {
            event.preventDefault();
        }

        if($(this).val().indexOf('.') !== -1 && event.keyCode == 190)
            event.preventDefault(); 
        //if a decimal has been added, disable the "."-button

    });

TO some extent i have got with the help of some other site. And also wanted if the user copy and paste the correct IP, then it should accept, else it should not allow him to paste.

DEMO

I wanted to validate only for IP address accepting only 3 three dots after some numbers

ex: Valid: 191.123.121.202 is valid which has 3 dots after some decimal. Invalid : 191..123.121.202 is invalid where 2 dots are in sequence

Whole Point: wanted a robust IP validator

$("input.onlynumberdecimal").keydown(function (event) {

        console.log(event.keyCode);

        if (event.shiftKey == true) {
            event.preventDefault();
        }

        if ((event.keyCode >= 48 && event.keyCode <= 57) || 
            (event.keyCode >= 96 && event.keyCode <= 105) || 
            event.keyCode == 8 || event.keyCode == 9 || event.keyCode == 37 ||
            event.keyCode == 39 || event.keyCode == 46 || event.keyCode == 190) {

        } else {
            event.preventDefault();
        }

        if($(this).val().indexOf('.') !== -1 && event.keyCode == 190)
            event.preventDefault(); 
        //if a decimal has been added, disable the "."-button

    });

TO some extent i have got with the help of some other site. And also wanted if the user copy and paste the correct IP, then it should accept, else it should not allow him to paste.

DEMO

• javascript
• jquery
• logic

• possible duplicate of Input box for changing IP Address – Jonathon Reinhart Commented Aug 1, 2013 at 6:50
• 1 It's more typical to do validation on blur() rather than on keypress/down(). It's much easier to validate the whole text at once and there are far fewer edge cases to think about (like your example of copy/paste). – Phylogenesis Commented Aug 1, 2013 at 6:54
• 1 And even better onsubmit and then again on the server – mplungjan Commented Aug 1, 2013 at 6:56

9 Answers 9

DEMO

try this

var pattern = /\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b/;
x = 46;
$('input[type="text"]').keypress(function (e) {
    if (e.which != 8 && e.which != 0 && e.which != x && (e.which < 48 || e.which > 57)) {
        console.log(e.which);
        return false;
    }
}).keyup(function () {
    var this1 = $(this);
    if (!pattern.test(this1.val())) {
        $('#validate_ip').text('Not Valid IP');
        while (this1.val().indexOf("..") !== -1) {
            this1.val(this1.val().replace('..', '.'));
        }
        x = 46;
    } else {
        x = 0;
        var lastChar = this1.val().substr(this1.val().length - 1);
        if (lastChar == '.') {
            this1.val(this1.val().slice(0, -1));
        }
        var ip = this1.val().split('.');
        if (ip.length == 4) {
            $('#validate_ip').text('Valid IP');
        }
    }
});

Update for validating IP address with port numbers.

Ex. 192.168.2.100:27896

var pattern = /\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\:([0-9]{1,4}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5])\b/;
x = 46;
$('input[type="text"]').keypress(function (e) {
    console.log(e.which);
    if (e.which != 8 && e.which != 0 && e.which != x && e.which !=58 && (e.which < 48 || e.which > 57)) {
        console.log(e.which);
        return false;
    }
}).keyup(function () {
    var this1 = $(this);
    if (!pattern.test(this1.val())) {
        $('#validate_ip').text('Not Valid IP');
        while (this1.val().indexOf("..") !== -1) {
            this1.val(this1.val().replace('..', '.'));
        }
        x = 46;
    } else {
        x = 0;
        var lastChar = this1.val().substr(this1.val().length - 1);
        if (lastChar == '.') {
            this1.val(this1.val().slice(0, -1));
        }
        var ip = this1.val().split('.');
        if (ip.length == 4) {
            $('#validate_ip').text('Valid IP');
        }
    }
});

WORKING FIDDLE

use regex for this and regex for ipv4 address is

/((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(.|$)){4}/

function validateIP(ipAddress){ ipv4Re = new RegExp('^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.|$)){4}', 'i'); if(ipv4Re.test(ipAddress)){ return "its a vaild address"} else return "its an invalid address"}

it will validate :

• 0.0.0.0
• 255.255.255.255
• 191.123.121.202

and invalidate: - 191..123.121.202

function isIpAddress(s) {
  if (typeof s !== 'string') { return false; }
  // There must be 4 parts separated by dots.
  var parts = s.split('.');
  if (parts.length !== 4) { return false; }
  // Each of the four parts must be an integer in the range 0 to 255.
  for (var i = 0; i < 4; ++i) {
    var part = parts[i];
    // Each part must consist of 1 to 3 decimal digits.
    if (!/^\d{1,3}$/.test(part)) { return false; }
    var n = +part;
    if (0 > n || n > 0xff) { return false; }
  }
  return true;
}

Try this.

<SCRIPT language="JavaScript">
function verifydata( ining )
{
    errorlog = ""

    // CHECK ALL THE FIELDS TO VERIFY THEIR EXISTENCE
    if ( ining.ipstart.value == "" )
        errorlog += "Starting IP Address is blank.\n"
    if ( ining.ipend.value == "" )
        errorlog += "Ending IP Address is blank.\n"
    if ( !(/^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/.test(ining.ipstart.value) ) )
        errorlog += "Incorrect Starting IP Address Format.\n"
    if ( !(/^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/.test(ining.ipend.value) ) )
        errorlog += "Incorrect Ending IP Address Format.\n"

}
</SCRIPT>

OR You can use the jQuery Mask Plugin. So simple to use and it will add the . (dots) and placeholders for numbers would be marked.

Following solution will validate the entered IP address value including format & it's value also. It will accept min 0.0.0.0 and max 255.255.255.255. If invalid IP address entered then code will highlight the input control in pink color & clear the text otherwise will keep valid value as entered.

Put the input tag on page:

<input type="text" name="IpAddress" id="IpAddress" class="input-medium" onkeypress="return IPAddressKeyOnly(event)" onblur="confirmIPAddress();"/>

Add following methods in appropriate java script file or include on the page it self.

1) To handle the key press event:

function IPAddressKeyOnly(e) {
    var keyCode = e.keyCode == 0 ? e.charCode : e.keyCode;
    if (keyCode != 46 && keyCode > 31 && (keyCode < 48 || keyCode > 57))
       return false;
    return true;
}

2) To handle the correct IP address value validation:

function confirmIPAddress() {
   var ip = document.getElementById("IpAddress");
   if (ip.value.length >0 && ip.value.length<=15 ) { 
      ip.style.background = "white";
      var ipSlot=ip.value.split(".");
      if(ipSlot.length==4){
        for (var i=0;i<ipSlot.length;i++){
        var l=ipSlot[i].length;
            if (l >0 && l<=3){
                if(ipSlot[i]>=0 && ipSlot[i]<256){}
                else{ip.value = "";ip.style.background = "pink";break ;return false;}
            }else{
                ip.value = "";ip.style.background = "pink";break ;return false;
            }
        }
    }else{ip.value = "";ip.style.background = "pink";return false; }
}
else{ip.value = "";ip.style.background = "pink";}

}

try it once .

//Check Format
var ip = ip.split(".");

if (ip.length != 4) {
    return false;
}

//Check Numbers
for (var c = 0; c < 4; c++) {
    //Perform Test
    if(isNaN(parseFloat(ip[c])) || !isFinite(ip[c]) || ip[c] < 0 || ip[c] > 255 || ip[c].indexOf(" ") !== -1 || ip[c].match(/^-\d+$/)){

         return false;
    }
}
return true;

        //invalid ip send
        ipvalidation('256.0.0.0');

        //ip validation function
        function ipvalidation(x){
            limit = 255; 
            [ii, xx, yy, cc] = x.split('.');
            if(ii <= limit && xx <= limit && yy <= limit && cc <= limit){
                alert('valid ip');
            } else {
                alert('invalid ip');
            }
        }

Not using regex

Just putting another one in here that is slightly more verbose but still a small implementation:

let isIpv4 = ip => {
  // Test length to see that we have a valid ipv4 address
  // Must consist of 4 values seperated by .
  // Each char must be a number between 0 and 255 and not empty
  return ip !== '' && ip.split('.').filter( n => ( n !== '' && n >= 0 && n <= 255 ) ).length === 4
}

console.log(isIpv4('192.168.2.1')) // True
console.log(isIpv4('255.255.255')) // False
console.log(isIpv4('255.ab.255.255')) // False