Is it any limit for POST data size in Ajax?

Is it any POST Limit in Ajax?

No, the HTTP specification doesn't impose a specific size limit for posts. However it depends on the Web Server which you are using or the programming technology used to process the form submission.

In ASP.NET MVC you can try this:

<system.webServer>
<security>
    <requestFiltering>
        <requestLimits maxAllowedContentLength="1000000" />
    </requestFiltering>
</security>

JSON has a maximum length! I need to increase this value. In web.config add the following:

<appSettings>
  <add key="aspnet:MaxJsonDeserializerMembers" value="150000" />
</appSettings>

The HTTP spec doesn't defining a limitation of POST data size.

But using ASP.NET MVC, there could be a POST data limitation, try to increase it in your Web.Config file:

<system.webServer>
<security>
    <requestFiltering>
        <requestLimits maxAllowedContentLength="1000000" />
    </requestFiltering>
</security>

From MSDN:

Specifies the maximum length of content in a request, in bytes. The default value is 30000000.

This solved my problem:

<system.web.extensions>
    <scripting>
        <webServices>
            <jsonSerialization maxJsonLength="2147483647" />
        </webServices>
    </scripting>
</system.web.extensions>