diff --git a/docs/generators/javascript.md b/docs/generators/javascript.md
index e8b1fa4b511..a10b56ae084 100644
--- a/docs/generators/javascript.md
+++ b/docs/generators/javascript.md
@@ -43,7 +43,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |sourceFolder|source folder for generated code| |src|
 |useInheritance|use JavaScript prototype chains & delegation for inheritance| |true|
 |usePromises|use Promises as return values from the client API, instead of superagent callbacks| |false|
-|useURLSearchParams|use JS build-in UrlSearchParams, instead of deprecated npm lib 'querystring'| |false|
+|useURLSearchParams|use JS build-in UrlSearchParams, instead of deprecated npm lib 'querystring'| |true|
 
 ## IMPORT MAPPING
 
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClientCodegen.java
index 06d0c634ae8..3fbe56e863d 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClientCodegen.java
@@ -81,7 +81,7 @@ public class JavascriptClientCodegen extends DefaultCodegen implements CodegenCo
     protected boolean useES6 = true; // default is ES6
     @Setter protected String npmRepository = null;
     @Getter private String modelPropertyNaming = "camelCase";
-    @Setter protected boolean useURLSearchParams = false;
+    @Setter protected boolean useURLSearchParams = true;
 
     public JavascriptClientCodegen() {
         super();
@@ -194,7 +194,7 @@ public class JavascriptClientCodegen extends DefaultCodegen implements CodegenCo
         cliOptions.add(new CliOption(NPM_REPOSITORY, "Use this property to set an url your private npmRepo in the package.json"));
         cliOptions.add(new CliOption(USE_URL_SEARCH_PARAMS,
                 "use JS build-in UrlSearchParams, instead of deprecated npm lib 'querystring'")
-                .defaultValue(Boolean.FALSE.toString())
+                .defaultValue(Boolean.TRUE.toString())
         );
 
         supportedLibraries.put(LIBRARY_JAVASCRIPT, "JavaScript client library");
diff --git a/samples/client/petstore/javascript-es6/src/ApiClient.js b/samples/client/petstore/javascript-es6/src/ApiClient.js
index 271dc70cf0e..22d36a30f7f 100644
--- a/samples/client/petstore/javascript-es6/src/ApiClient.js
+++ b/samples/client/petstore/javascript-es6/src/ApiClient.js
@@ -13,7 +13,6 @@
 
 
 import superagent from "superagent";
-import querystring from "querystring";
 
 /**
 * @module ApiClient
@@ -443,7 +442,10 @@ class ApiClient {
         }
 
         if (contentType === 'application/x-www-form-urlencoded') {
-            request.send(querystring.stringify(this.normalizeParams(formParams)));
+            let normalizedParams = this.normalizeParams(formParams)
+            let urlSearchParams =  new URLSearchParams(normalizedParams);
+            let queryString = urlSearchParams.toString();
+            request.send(queryString);
         } else if (contentType == 'multipart/form-data') {
             var _formParams = this.normalizeParams(formParams);
             for (var key in _formParams) {
diff --git a/samples/client/petstore/javascript-promise-es6/src/ApiClient.js b/samples/client/petstore/javascript-promise-es6/src/ApiClient.js
index 12762f0d47c..fc801fb55ee 100644
--- a/samples/client/petstore/javascript-promise-es6/src/ApiClient.js
+++ b/samples/client/petstore/javascript-promise-es6/src/ApiClient.js
@@ -13,7 +13,6 @@
 
 
 import superagent from "superagent";
-import querystring from "querystring";
 
 /**
 * @module ApiClient
@@ -435,7 +434,10 @@ class ApiClient {
         }
 
         if (contentType === 'application/x-www-form-urlencoded') {
-            request.send(querystring.stringify(this.normalizeParams(formParams)));
+            let normalizedParams = this.normalizeParams(formParams)
+            let urlSearchParams =  new URLSearchParams(normalizedParams);
+            let queryString = urlSearchParams.toString();
+            request.send(queryString);
         } else if (contentType == 'multipart/form-data') {
             var _formParams = this.normalizeParams(formParams);
             for (var key in _formParams) {