How to get external (public) IP in Delphi

Question

I need to get my external (public) IP address from Delphi.

The same IP that is shown by www.whatismyip.com for example.

How can I do that ? Winsock doesn't allow this.

By external IP address, do you mean your internet accessible IP address? Or do you mean a local network address that is not 127.0.0.1? — Tremmors, Aug 10 '11 at 17:57
internet accessible address, the same that is shown by www.whatismyip.com — chubbyk, Aug 10 '11 at 18:00
This question shows your computer's actual IP addresses; http://stackoverflow.com/questions/576538/delphi-how-to-get-all-local-ips — Warren P, Aug 10 '11 at 18:44
This is not possible in general case, ask about your specific problem. — Premature Optimization, Aug 10 '11 at 19:15
Who says you only have one? Anyway, Downvoter* has a point that you need to sketch your problem more. What do you think you need the external IP for? — Marco van de Voort, Aug 12 '11 at 09:02

pedro.olimpio · Answer 1 · 2015-10-13T11:45:07.880

10

You can use this website: http://ipinfo.io/json. It returns the information about your current internet connection in JSON format.

In delphi you need use IdHTTP this way: IdHTTP1.Get('http://ipinfo.io/json') and it will returns a string with all the data. You can use a JSONinterpreter you like or you can use the lkJSON as the following example:

json := TlkJSON.ParseText(MainEstrutura.IdHTTP1.Get('http://ipinfo.io/json')) as TlkJSONobject;

str := json.Field['ip'].Value;

I hope help you.

edited Oct 13 '15 at 11:45

answered Jan 28 '15 at 21:15

pedro.olimpio

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If you use `http://ipinfo.io/ip` instead, it returns just the IP by itself in plain text without wrapping it in JSON that has to be parsed. – Remy Lebeau Oct 15 '15 at 00:28
As the code in this answer you need use: `http://ipinfo.io/json` to get all information about this IP – pedro.olimpio Oct 15 '15 at 14:01
2

The OP did not ask to retrieve all the details about the IP, only to retrieve the IP itself. So `/json` is overkill when `/ip` will suffice. If you read the website's documentation, individual fields can be retrieved by themselves. – Remy Lebeau Oct 15 '15 at 20:18

score 7 · Accepted Answer · edited Aug 10 '11 at 22:52

7

I don't think you can. Well, you could call some service that tells you what your IP address appears to be, ( ex: http://www.whatismyip.com/ ) and figure it out from the response. But I don't think anything on your PC will be able to tell you what your IP address looks like, to the outside world.

Untested, but I think you can do this with Indy:

MyPublicIP := IdHTTP1.Get('http://automation.whatismyip.com/n09230945.asp');

Please review the rules/policy at: http://www.whatismyip.com/faq/automation.asp before using this.

edited Aug 10 '11 at 22:52

answered Aug 10 '11 at 18:00

Chris Thornton

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... and the reason is that your public address is not necessarily attached to your computer. Pretty often, it's assigned to an external router, which is an entirely different computer to all effects. – Álvaro González Aug 10 '11 at 18:10
Yes. Public IP and adapter with default gateway are two different things. – Marco van de Voort Aug 12 '11 at 09:03

Salim Lachdhaf · Answer 3 · 2017-06-02T16:54:15.260

6

this works for me:

  uses JSON,IdHTTP;
  function GetIP():String;
  var  LJsonObj   : TJSONObject;
  str:string;
  http : TIdHttp;
  begin
    str:='';
    http:=TIdHTTP.Create(nil);
    try
        str:=http.Get('http://ipinfo.io/json');
        LJsonObj:= TJSONObject.ParseJSONValue(TEncoding.ASCII.GetBytes(str),0)           as TJSONObject;
        str := LJsonObj.Get('ip').JsonValue.Value;
        LJsonObj.Free;
        http.Free;
    Except
    end;
    result:=str;
end;

edited Jun 02 '17 at 16:54

answered Oct 14 '15 at 22:05

Salim Lachdhaf

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I prefer to use services that report the IP by itself as plain text without any extra metadata formatting. For example: `function GetIP: String; begin with TIdHTTP.Create do try Result := http.Get('http://ipinfo.io/ip'); finally Free; end; end;` – Remy Lebeau Oct 15 '15 at 00:27
@RemyLebeau The best and simple solution ! (but replace `http.Get` with `Get`) – Marus Gradinaru Jul 20 '20 at 13:49

score 2 · Answer 4 · answered Aug 15 '11 at 03:12

From memory, untested:

function GetMyHostAddress: string;
var
   http: IWinHttpRequest;
begin
   http := CreateOleObject('WinHttp.WinHttpRequest5.1') as IWinHttpRequest;
   http.Open('GET', 'http://automation.whatismyip.com/n09230945.asp', False);
   http.Send(EmptyParam);

   if http.StatusCode = 200 then
      Result := http.ResponseText
   else
      Result := '';
end;

score 0 · Answer 5 · answered Nov 07 '15 at 13:03

Function GetMyIP:string;
var
  xmlhttp:olevariant;
  s,p:integer;
  temp:string;
begin
  result:=emptystr;
  xmlhttp:=CreateOleObject('Microsoft.XMLHTTP');
  try
    xmlhttp.open('GET', 'http://www.findipinfo.com/', false);
    xmlhttp.SetRequestHeader('User-Agent','Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3');
    xmlhttp.send(null);
  except
    exit;
  end;
  if(xmlhttp.status = 200) then
  temp:=trim(VarToStr(xmlhttp.responseText));
  xmlhttp:=Unassigned;
  s:=pos('Address Is:',temp);
  if s>0 then
  inc(s,11)
  else
  exit;
  temp:=copy(temp,s,30);
  s:=pos('<',temp);
  if s=0 then exit
  else
  dec(s);
  result:=trim(copy(temp,1,s));
end;

How to get external (public) IP in Delphi

5 Answers5