Convert "1.79769313486232E+308" to double without OverflowException?

Unfortunately this value is greater than double.MaxValue, hence the exception.

As codekaizen suggests, you could hard-code a test for the string. A better (IMO) alternative if you're the one producing the string in the first place is to use the "r" format specifier. Then the string you produce will be "1.7976931348623157E+308" instead, which then parses correctly:

string s = double.MaxValue.ToString("r");
double d = double.Parse(s); // No exception

Obviously that's no help if you don't have control over the data - but then you should understand you're likely to be losing data already in that case.

The problem is likely due to the fact that Double.MaxValue was converted to a string, and when the string is output, not all the digits are output, instead it is rounded. Parsing this value overflows the double.

Using Double.TryParse and subsequently checking equality on the string "1.79769313486232E+308" in case of failure and substituting Double.MaxValue should be a quick workaround, if you need to keep the string the way it is.

EDIT: Of course, if you don't need to keep the string the way it is, use the Round Trip format specifier to produce the string in the first place, as Jon describes in his answer.