diff --git a/package-lock.json b/package-lock.json
index 22a5fe98..173bd766 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -6523,6 +6523,15 @@
         }
       }
     },
+    "karma-debug-launcher": {
+      "version": "0.0.3",
+      "resolved": "https://registry.npmjs.org/karma-debug-launcher/-/karma-debug-launcher-0.0.3.tgz",
+      "integrity": "sha512-YYGby+j0hC4FIyfjgddlpxB7eQWYkVhsYlThqTQoZXmGM2XM87FII22VePuhBbD7xJaM92rvcXsgWAviS94pSA==",
+      "dev": true,
+      "requires": {
+        "open": "^7.3.0"
+      }
+    },
     "karma-env-preprocessor": {
       "version": "0.1.1",
       "resolved": "https://registry.npmjs.org/karma-env-preprocessor/-/karma-env-preprocessor-0.1.1.tgz",
@@ -8164,6 +8173,27 @@
         "wrappy": "1"
       }
     },
+    "open": {
+      "version": "7.3.0",
+      "resolved": "https://registry.npmjs.org/open/-/open-7.3.0.tgz",
+      "integrity": "sha512-mgLwQIx2F/ye9SmbrUkurZCnkoXyXyu9EbHtJZrICjVAJfyMArdHp3KkixGdZx1ZHFPNIwl0DDM1dFFqXbTLZw==",
+      "dev": true,
+      "requires": {
+        "is-docker": "^2.0.0",
+        "is-wsl": "^2.1.1"
+      },
+      "dependencies": {
+        "is-wsl": {
+          "version": "2.2.0",
+          "resolved": "https://registry.npmjs.org/is-wsl/-/is-wsl-2.2.0.tgz",
+          "integrity": "sha512-fKzAra0rGJUUBwGBgNkHZuToZcn+TtXHpeCgmkMJMMYx1sQDYaCSyjJBSCa2nH1DGm7s3n1oBnohoVTBaN7Lww==",
+          "dev": true,
+          "requires": {
+            "is-docker": "^2.0.0"
+          }
+        }
+      }
+    },
     "optionator": {
       "version": "0.9.1",
       "resolved": "https://registry.npmjs.org/optionator/-/optionator-0.9.1.tgz",
diff --git a/package.json b/package.json
index a68a4c6a..1ec0afaf 100644
--- a/package.json
+++ b/package.json
@@ -5,6 +5,9 @@
   "scripts": {
     "all": "run-s lint test distro test:distro",
     "lint": "eslint .",
+    "start": "SINGLE_START=modeler npm run dev",
+    "start:viewer": "SINGLE_START=viewer npm run dev",
+    "start:navigated-viewer": "SINGLE_START=navigated-viewer npm run dev",
     "dev": "npm test -- --auto-watch --no-single-run",
     "test": "karma start test/config/karma.unit.js",
     "distro": "node tasks/build-distro.js",
@@ -56,6 +59,7 @@
     "karma": "^5.2.3",
     "karma-chrome-launcher": "^3.1.0",
     "karma-coverage": "^2.0.3",
+    "karma-debug-launcher": "0.0.3",
     "karma-env-preprocessor": "^0.1.1",
     "karma-firefox-launcher": "^2.1.0",
     "karma-ie-launcher": "^1.0.0",
diff --git a/test/config/karma.unit.js b/test/config/karma.unit.js
index 458b8364..4154a1b7 100644
--- a/test/config/karma.unit.js
+++ b/test/config/karma.unit.js
@@ -2,6 +2,8 @@ var path = require('path');
 
 var collectTranslations = process.env.COLLECT_TRANSLATIONS;
 
+var singleStart = process.env.SINGLE_START;
+
 var coverage = process.env.COVERAGE;
 
 // configures browsers to run test against
@@ -90,10 +92,15 @@ module.exports = function(karma) {
   };
 
   if (collectTranslations) {
-    config.plugins = [].concat(config.plugins || [], 'karma-*', require('./translation-reporter'));
+    config.plugins = [].concat(config.plugins || ['karma-*'], require('./translation-reporter'));
     config.reporters = [].concat(config.reporters || [], 'translation-reporter');
     config.envPreprocessor = [].concat(config.envPreprocessor || [], 'COLLECT_TRANSLATIONS');
   }
 
+  if (singleStart) {
+    config.browsers = [].concat(config.browsers, 'Debug');
+    config.envPreprocessor = [].concat(config.envPreprocessor || [], 'SINGLE_START');
+  }
+
   karma.set(config);
 };
diff --git a/test/spec/ModelerSpec.js b/test/spec/ModelerSpec.js
index 0afd5eb0..2e266156 100644
--- a/test/spec/ModelerSpec.js
+++ b/test/spec/ModelerSpec.js
@@ -15,6 +15,9 @@ import {
 } from 'test/TestHelper';
 
 
+var singleStart = window.__env__ && window.__env__.SINGLE_START === 'modeler';
+
+
 describe('Modeler', function() {
 
   var container;
@@ -46,7 +49,7 @@ describe('Modeler', function() {
   }
 
 
-  it('should import simple process', function() {
+  (singleStart ? it.only : it)('should import simple process', function() {
     var xml = require('../fixtures/bpmn/simple.bpmn');
     return createModeler(xml).then(function(result) {
 
diff --git a/test/spec/NavigatedViewerSpec.js b/test/spec/NavigatedViewerSpec.js
index 853206b4..2717b166 100644
--- a/test/spec/NavigatedViewerSpec.js
+++ b/test/spec/NavigatedViewerSpec.js
@@ -8,6 +8,8 @@ import {
   createViewer
 } from 'test/TestHelper';
 
+var singleStart = window.__env__ && window.__env__.SINGLE_START === 'navigated-viewer';
+
 
 describe('NavigatedViewer', function() {
 
@@ -18,7 +20,7 @@ describe('NavigatedViewer', function() {
   });
 
 
-  it('should import simple process', function() {
+  (singleStart ? it.only : it)('should import simple process', function() {
     var xml = require('../fixtures/bpmn/simple.bpmn');
     return createViewer(container, NavigatedViewer, xml).then(function(result) {
 
diff --git a/test/spec/ViewerSpec.js b/test/spec/ViewerSpec.js
index 3840fc5c..93fff9db 100644
--- a/test/spec/ViewerSpec.js
+++ b/test/spec/ViewerSpec.js
@@ -12,6 +12,8 @@ import {
   createViewer
 } from 'test/TestHelper';
 
+var singleStart = window.__env__ && window.__env__.SINGLE_START === 'viewer';
+
 
 describe('Viewer', function() {
 
@@ -22,7 +24,7 @@ describe('Viewer', function() {
   });
 
 
-  it('should import simple process', function() {
+  (singleStart ? it.only : it)('should import simple process', function() {
     var xml = require('../fixtures/bpmn/simple.bpmn');
 
     // when