diff --git a/src/htmx.js b/src/htmx.js
index 3ae640d2..7a3fef2b 100644
--- a/src/htmx.js
+++ b/src/htmx.js
@@ -1116,10 +1116,14 @@ var htmx = htmx || (function () {
             var encodedParameters = null;
             forEach(getExtensions(elt), function (extension) {
                 if (encodedParameters == null) {
-                    extension.encodeParameters(xhr, filteredParameters, elt);
+                    encodedParameters = extension.encodeParameters(xhr, filteredParameters, elt);
                 }
             });
-            return urlEncode(filteredParameters);
+            if (encodedParameters != null) {
+                return encodedParameters;
+            } else {
+                return urlEncode(filteredParameters);
+            }
         }
 
         function issueAjaxRequest(elt, verb, path, eventTarget) {
diff --git a/test/extensions/json-enc.js b/test/extensions/json-enc.js
new file mode 100644
index 00000000..8dc25a62
--- /dev/null
+++ b/test/extensions/json-enc.js
@@ -0,0 +1,143 @@
+//
+describe("json-enc extension", function() {
+    beforeEach(function () {
+        this.server = makeServer();
+        clearWorkArea();
+        htmx.defineExtension('json-enc', {
+            encodeParameters : function(xhr, parameters, elt) {
+                xhr.requestHeaders['Content-Type'] = 'application/json';
+                xhr.overrideMimeType('text/json');
+                return (JSON.stringify(parameters));
+            }
+        });
+    });
+    afterEach(function () {
+        this.server.restore();
+        clearWorkArea();
+    });
+
+    it('handles basic post properly', function () {
+        var jsonResponseBody = JSON.stringify({});
+        this.server.respondWith("POST", "/test", jsonResponseBody);
+        var div = make("<div hx-post='/test' hx-ext='json-enc'>click me</div>");
+        div.click();
+        this.server.respond();
+        this.server.lastRequest.response.should.equal("{}");
+    })
+
+    it('handles basic put properly', function () {
+        var jsonResponseBody = JSON.stringify({});
+        this.server.respondWith("PUT", "/test", jsonResponseBody);
+        var div = make('<div hx-put="/test" hx-ext="json-enc">click me</div>');
+        div.click();
+        this.server.respond();
+        this.server.lastRequest.response.should.equal("{}");
+    })
+
+    it('handles basic patch properly', function () {
+        var jsonResponseBody = JSON.stringify({});
+        this.server.respondWith("PATCH", "/test", jsonResponseBody);
+        var div = make('<div hx-patch="/test" hx-ext="json-enc">click me</div>');
+        div.click();
+        this.server.respond();
+        this.server.lastRequest.response.should.equal("{}");
+    })
+
+    it('handles basic delete properly', function () {
+        var jsonResponseBody = JSON.stringify({});
+        this.server.respondWith("DELETE", "/test", jsonResponseBody);
+        var div = make('<div hx-delete="/test" hx-ext="json-enc">click me</div>');
+        div.click();
+        this.server.respond();
+        this.server.lastRequest.response.should.equal("{}");
+    })
+
+    it('handles post with form parameters', function () {
+
+        this.server.respondWith("POST", "/test", function (xhr) {
+            var values = JSON.parse(xhr.requestBody);
+            values.should.have.keys("username","password");
+            values["username"].should.be.equal("joe");
+            values["password"].should.be.equal("123456");
+            var ans = { "passwordok": values["password"] == "123456"};
+            xhr.respond(200, {}, JSON.stringify(ans));
+        });
+
+        var html = make('<form hx-post="/test" hx-ext="json-enc" > ' +
+            '<input type="text"  name="username" value="joe"> ' +
+            '<input type="password"  name="password" value="123456"> ' +
+        '<button  id="btnSubmit">Submit</button> ');
+
+        byId("btnSubmit").click();
+        this.server.respond();
+        this.server.lastRequest.response.should.equal('{"passwordok":true}');
+    })
+
+    it('handles put with form parameters', function () {
+
+        this.server.respondWith("PUT", "/test", function (xhr) {
+            var values = JSON.parse(xhr.requestBody);
+            values.should.have.keys("username","password");
+            values["username"].should.be.equal("joe");
+            values["password"].should.be.equal("123456");
+            var ans = { "passwordok": values["password"] == "123456"};
+            xhr.respond(200, {}, JSON.stringify(ans));
+        });
+
+        var html = make('<form hx-put="/test" hx-ext="json-enc" > ' +
+            '<input type="text"  name="username" value="joe"> ' +
+            '<input type="password"  name="password" value="123456"> ' +
+        '<button  id="btnSubmit">Submit</button> ');
+
+        byId("btnSubmit").click();
+        this.server.respond();
+        this.server.lastRequest.response.should.equal('{"passwordok":true}');
+    })
+
+
+    it('handles patch with form parameters', function () {
+
+        this.server.respondWith("PATCH", "/test", function (xhr) {
+            var values = JSON.parse(xhr.requestBody);
+            values.should.have.keys("username","password");
+            values["username"].should.be.equal("joe");
+            values["password"].should.be.equal("123456");
+            var ans = { "passwordok": values["password"] == "123456"};
+            xhr.respond(200, {}, JSON.stringify(ans));
+        });
+
+        var html = make('<form hx-patch="/test" hx-ext="json-enc" > ' +
+            '<input type="text"  name="username" value="joe"> ' +
+            '<input type="password"  name="password" value="123456"> ' +
+        '<button  id="btnSubmit">Submit</button> ');
+
+        byId("btnSubmit").click();
+        this.server.respond();
+        this.server.lastRequest.response.should.equal('{"passwordok":true}');
+    })
+
+    it('handles delete with form parameters', function () {
+
+        this.server.respondWith("DELETE", "/test", function (xhr) {
+            var values = JSON.parse(xhr.requestBody);
+            values.should.have.keys("username","password");
+            values["username"].should.be.equal("joe");
+            values["password"].should.be.equal("123456");
+            var ans = { "passwordok": values["password"] == "123456"};
+            xhr.respond(200, {}, JSON.stringify(ans));
+        });
+
+        var html = make('<form hx-delete="/test" hx-ext="json-enc" > ' +
+            '<input type="text"  name="username" value="joe"> ' +
+            '<input type="password"  name="password" value="123456"> ' +
+        '<button  id="btnSubmit">Submit</button> ');
+
+        byId("btnSubmit").click();
+        this.server.respond();
+        this.server.lastRequest.response.should.equal('{"passwordok":true}');
+    })
+
+
+
+});
+
diff --git a/test/index.html b/test/index.html
index 66f6c172..fd667f66 100644
--- a/test/index.html
+++ b/test/index.html
@@ -87,7 +87,7 @@
 <script src="extensions/rails-method.js"></script>
 <script src="extensions/debug.js"></script>
 <script src="extensions/morphdom-swap.js"></script>
-
+<script src="extensions/json-enc.js"></script>
 
 <!-- events last so they don't screw up other tests -->
 <script src="core/events.js"></script>
diff --git a/www/docs.md b/www/docs.md
index 605d3057..1ba7dbe1 100644
--- a/www/docs.md
+++ b/www/docs.md
@@ -97,7 +97,7 @@ It can be used via [NPM](https://www.npmjs.com/) as "`htmx.org`" or downloaded o
 
 ## <a name="ajax"></a> [AJAX](#ajax)
 
-The core feature of htmx is a set of attributes that allow you to issue AJAX requests directly from HTML:
+The core of htmx is a set of attributes that allow you to issue AJAX requests directly from HTML:
 
 * [hx-get](/attributes/hx-get) - Issues a `GET` request to the given URL
 * [hx-post](/attributes/hx-post) - Issues a `POST` request to the given URL
@@ -492,11 +492,13 @@ If you are interested in adding your own extension to htmx, please [see the exte
 
 Htmx offers some officially supported extensions that are tested against the htmx code base, including:
 
-* [`debug`](/official-extensions#debug) - an extension for htmx debugging a particular element
-* [`rails-method`](/official-extensions#rails-method) - an extension for including the `_method` parameter 
-[that rails uses](https://guides.rubyonrails.org/form_helpers.html#how-do-forms-with-patch-put-or-delete-methods-work-questionmark).
+* [`json-enc`](/official-extensions#json-enc) - use JSON encoding in the body of requests, rather than the default `x-www-form-urlencoded`
 * [`morphdom-swap`](/official-extensions#morphdom-swap) - an extension for using the 
 [morphdom](https://github.com/patrick-steele-idem/morphdom) library as the swapping mechanism in htmx.
+* [`debug`](/official-extensions#debug) - an extension for debugging of a particular element using htmx
+* [`rails-method`](/official-extensions#rails-method) - an extension for including the `_method` parameter that 
+[that rails uses](https://guides.rubyonrails.org/form_helpers.html#how-do-forms-with-patch-put-or-delete-methods-work-questionmark)
+for non-`POST` or `GET` HTTP methods.
 
 See the [officially extensions](/official-extensions) page for a complete list.
 
diff --git a/www/official-extensions.md b/www/official-extensions.md
index 65c3333e..07e42658 100644
--- a/www/official-extensions.md
+++ b/www/official-extensions.md
@@ -93,4 +93,29 @@ htmx.defineExtension('morphdom-swap', {
         }
     }
 });
-```
\ No newline at end of file
+```
+
+### <a name="json-enc">[`json-enc`](#json-enc)
+
+#### Description
+
+This extension encodes parameters in JSON format instead of url format.
+
+#### Usage
+
+```html
+<div hx-post='/test' hx-ext='json-enc'>click me</div>
+```
+
+#### Source
+
+```javascript
+htmx.defineExtension('json-enc', {
+    encodeParameters : function(xhr, parameters, elt) {
+        xhr.requestHeaders['Content-Type'] = 'application/json';
+        xhr.overrideMimeType('text/json');
+        return (JSON.stringify(parameters));
+    }
+});
+
+```