diff --git a/src/bin/intern.ts b/src/bin/intern.ts
index fd4aaffd5..538e62281 100644
--- a/src/bin/intern.ts
+++ b/src/bin/intern.ts
@@ -20,7 +20,7 @@ getConfig()
       console.log(getConfigDescription(config));
     } else {
       if (!file) {
-        console.warn('No config file was loaded');
+        console.warn('No config file was loaded, using default one...');
       }
 
       intern.configure({ reporters: 'runner' });
@@ -29,9 +29,9 @@ getConfig()
       if (
         intern.environment === 'browser' &&
         ((intern.config.suites &&
-          intern.config.suites.some(pattern => pattern.endsWith('.ts'))) ||
+          intern.config.suites.some((pattern) => pattern.endsWith('.ts'))) ||
           (intern.config.plugins &&
-            intern.config.plugins.some(plugin =>
+            intern.config.plugins.some((plugin) =>
               plugin.script.endsWith('.ts')
             )))
       ) {
@@ -42,7 +42,7 @@ getConfig()
       return intern.run();
     }
   })
-  .catch(error => {
+  .catch((error) => {
     // If intern wasn't initialized, then this error won't have been
     // reported
     if (!error.reported) {
@@ -76,7 +76,7 @@ function printHelp(config: any, file?: string) {
 
   const internConfig = (<any>intern)._config;
   const opts = Object.keys(internConfig)
-    .map(key => {
+    .map((key) => {
       return { name: key, value: JSON.stringify(internConfig[key]) };
     })
     .sort((a, b) => {
diff --git a/src/index.html b/src/index.html
index cfcc57d3a..0d6b71a75 100644
--- a/src/index.html
+++ b/src/index.html
@@ -32,7 +32,7 @@
 				}
 
 				if (!result.file) {
-					console.warn('No config file was found');
+					console.warn('No config file was found, using default one...');
 				}
 
 				// Add the HTML and console reporters to the default
diff --git a/src/lib/browser/util.ts b/src/lib/browser/util.ts
index f58ac50b4..23b1c137c 100644
--- a/src/lib/browser/util.ts
+++ b/src/lib/browser/util.ts
@@ -1,10 +1,11 @@
 import { request, CancellablePromise, global } from '@theintern/common';
 
 import {
+  createDefaultConfig,
   getBasePath,
   loadConfig,
   parseArgs,
-  splitConfigPath
+  splitConfigPath,
 } from '../common/util';
 
 /**
@@ -30,31 +31,32 @@ export function getConfig(file?: string) {
     // If no config parameter was provided, try 'intern.json'. If that file
     // doesn't exist, just return the args
     file = resolvePath('intern.json', configBase);
-    load = loadConfig(file, loadText, args).catch(error => {
+    load = loadConfig(file, loadText, args).catch((error) => {
       if (error.message.indexOf('Request failed') === 0) {
         // The file wasn't found, clear the file name
         file = undefined;
-        return args;
+        return getSuitesExtension(configBase).then((extension) =>
+          createDefaultConfig(args, extension)
+        );
       }
-      throw error;
     });
   }
 
   return load
-    .then(config => {
+    .then((config) => {
       // If a basePath wasn't set in the config or via a query arg, and we
       // have a config file path, use that.
       if (file) {
         config.basePath = getBasePath(
           file,
           config.basePath,
-          path => path[0] === '/',
+          (path) => path[0] === '/',
           '/'
         );
       }
       return config;
     })
-    .then(config => ({ config, file }));
+    .then((config) => ({ config, file }));
 }
 
 /**
@@ -138,9 +140,10 @@ export type Url = {
 };
 export function parseUrl(url: string): Url | undefined {
   if (url) {
-    const match = /^(([^:\/?#]+):)?(\/\/(([^:\/?#]*)(:(\d+))?))?([^?#]*)(\?([^#]*))?(#(.*))?/.exec(
-      url
-    );
+    const match =
+      /^(([^:\/?#]+):)?(\/\/(([^:\/?#]*)(:(\d+))?))?([^?#]*)(\?([^#]*))?(#(.*))?/.exec(
+        url
+      );
     if (match) {
       return {
         protocol: match[2],
@@ -148,7 +151,7 @@ export function parseUrl(url: string): Url | undefined {
         port: match[7],
         path: match[8],
         query: match[10],
-        hash: match[12]
+        hash: match[12],
       };
     }
   }
@@ -158,7 +161,7 @@ export function parseUrl(url: string): Url | undefined {
  * Load a text resource
  */
 function loadText(path: string): CancellablePromise<any> {
-  return request(path).then(response => {
+  return request(path).then((response) => {
     if (!response.ok) {
       throw new Error('Request failed: ' + response.status);
     }
@@ -191,3 +194,13 @@ function resolvePath(path: string, basePath: string) {
 
   return basePathParts.join('/');
 }
+
+async function getSuitesExtension(basePath: string) {
+  return existsAsync(resolvePath('tsconfig.json', basePath)).then(
+    (tsconfigExists) => (tsconfigExists ? 'ts' : 'js')
+  );
+}
+
+async function existsAsync(filePath: string) {
+  return request(filePath, { method: 'HEAD' }).then((response) => response.ok);
+}
diff --git a/src/lib/common/util.ts b/src/lib/common/util.ts
index 7d48e6900..a9bc586c3 100644
--- a/src/lib/common/util.ts
+++ b/src/lib/common/util.ts
@@ -799,6 +799,18 @@ export function setOption(
   }
 }
 
+/**
+ * Create a default config to make zero-config running possible
+ */
+export function createDefaultConfig(baseConfig: any, suitesExtension: string) {
+  let config = Object.assign({}, baseConfig);
+  config.suites = [
+    `tests/**/*.${suitesExtension}`,
+    `src/**/*.spec.${suitesExtension}`,
+  ];
+  return config;
+}
+
 /**
  * Split a config path into a file name and a child config name.
  *
diff --git a/src/lib/node/util.ts b/src/lib/node/util.ts
index 0c002a12e..3fbced391 100644
--- a/src/lib/node/util.ts
+++ b/src/lib/node/util.ts
@@ -6,7 +6,7 @@ import {
   join,
   normalize,
   resolve,
-  sep
+  sep,
 } from 'path';
 import { parse } from 'shell-quote';
 import { RawSourceMap } from 'source-map';
@@ -16,10 +16,11 @@ import { Task, CancellablePromise } from '@theintern/common';
 
 import process from './process';
 import {
+  createDefaultConfig,
   getBasePath,
   loadConfig,
   parseArgs,
-  splitConfigPath
+  splitConfigPath,
 } from '../common/util';
 /**
  * Expand a list of glob patterns into a flat file list. Patterns may be simple
@@ -50,10 +51,10 @@ export function expandFiles(patterns?: string[] | string) {
   }
 
   const allPaths = includes
-    .map(pattern => glob(pattern, { ignore: excludes }))
+    .map((pattern) => glob(pattern, { ignore: excludes }))
     .reduce((allFiles, files) => allFiles.concat(files), paths);
   const uniquePaths: { [name: string]: boolean } = {};
-  allPaths.forEach(path => (uniquePaths[path] = true));
+  allPaths.forEach((path) => (uniquePaths[path] = true));
 
   return Object.keys(uniquePaths);
 }
@@ -116,15 +117,14 @@ export function getConfig(
       (error: NodeJS.ErrnoException) => {
         if (error.code === 'ENOENT') {
           file = undefined;
-          return args;
+          return createDefaultConfig(args, getSuitesExtension());
         }
-        throw error;
       }
     );
   }
 
   return load
-    .then(config => {
+    .then((config) => {
       // If a basePath wasn't set in the config or via a query arg, and we
       // have a config file path, use that.
       if (file) {
@@ -132,7 +132,7 @@ export function getConfig(
       }
       return config;
     })
-    .then(config => ({ config, file }));
+    .then((config) => ({ config, file }));
 }
 
 /**
@@ -213,7 +213,7 @@ export function transpileSource(filename: string, code: string) {
     {
       _compile(source: string) {
         code = source;
-      }
+      },
     } as any,
     filename
   );
@@ -222,4 +222,9 @@ export function transpileSource(filename: string, code: string) {
 }
 
 // Regex for matching sourceMappingUrl comments
-const sourceMapRegEx = /^(?:\/{2}[#@]{1,2}|\/\*)\s+sourceMappingURL\s*=\s*(data:(?:[^;]+;)+base64,)?(\S+)/;
+const sourceMapRegEx =
+  /^(?:\/{2}[#@]{1,2}|\/\*)\s+sourceMappingURL\s*=\s*(data:(?:[^;]+;)+base64,)?(\S+)/;
+
+function getSuitesExtension() {
+  return existsSync(resolve('tsconfig.json')) ? 'ts' : 'js';
+}