How to send double quote in -d parameter for curl.exe?

You can most certainly escape double quotes. How you do that depends on your operating system and shell, which you fail to specify. On Windows, you'd use the ^ as the escape character.

You can also do this:

curl [...] -d @filename 

...which reads post data from a file called filename.

Google and/or man is your friend.

http://curl.haxx.se/docs/manpage.html

For the escaping of double quote question, I'm finding that tripling the doublequotes works from the shell:

curl -d {"""foo""":"""bar"""}

while doubling the doublequotes works from within a batch file:

curl -d {""foo"":""bar""}

Which is quite annoying for testing in the shell first.

My curl.exe works with this form:

-d "{\"param\":\"value\"}"

i.e. doublequotes around data, and doublequotes masked with backslash inside

You can surround the data with single quotes and use double quotes inside.

Example in PowerShell

curl.exe https://httpbin.org/anything `
    -H 'Content-Type: application/json' `
    -d '{ "this": "is proper json" }'.Replace('"', '""')

Please note that cURL is built into Windows 10, but PowerShell shadows it with an alias, so you have to use curl.exe