How to decode response with zlib in fiddler - fiddler

Question

I know there is Response body is encoded. Click to decode but it dosen't work.
The response I get is encoded by zlib not gzip and there is no Content-Encoding: gzip in response header.
Now I can save the response body to a file and then decode it by Python, but I really want to see the pretty content just in fiddler.
What should I do?

Answer 1

I don't have enough rep. to comment, but I improved PaleNeutron's snippet.
Fix request decoding
Added logic to check for the zlib header so we don't double decode and create an empty request/response
In the FiddlerScript tab:
public static ContextAction("Force Decode (zlib)")
function AddEncoding(oSessions: Fiddler.Session[]){
for (var x:int = 0; x < oSessions.Length; x++){
if (oSessions[x].oRequest.headers["Content-Encoding"]=="zlib"){
oSessions[x].oRequest.headers["Content-Encoding"]="deflate";
oSessions[x].utilDecodeRequest();
}
if (oSessions[x].oResponse.headers["Content-Encoding"]=="zlib"){
oSessions[x].oResponse.headers["Content-Encoding"]="deflate";
oSessions[x].utilDecodeResponse();
}
}
UI.actUpdateInspector(true,true);
}

Answer 2

You can add or edit headers in Fiddler. Go to the Headers inspector and then select the Unlock for Editing option from the Edit menu. Then right-click on the headers and choose Add or Edit Header in the context menu.
Thus you can add/modify Content-Encoding.
You can also do that in FiddlerScript.

Answer 3

Add this to fiddler script
public static ContextAction("force decode with deflate")
function AddEncoding(oSessions: Fiddler.Session[]){
for (var x:int = 0; x < oSessions.Length; x++){
oSessions[x].utilDecodeRequest();
oSessions[x].oResponse.headers["Content-Encoding"]="deflate"
oSessions[x].utilDecodeResponse();
}
UI.actUpdateInspector(true,true);
}
And force decode with deflate choice will appear in the right-click menu.