diff --git a/package.json b/package.json
index cd43e6c..2727b3b 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,8 @@
     "name": "pegjs-dev",
     "private": true,
     "workspaces": [
-        "packages/*"
+        "packages/*",
+        "tools/*"
     ],
     "scripts": {
         "lint": "gulp lint",
@@ -11,8 +12,8 @@
         "build:parser": "gulp build:parser",
         "build:dist": "rollup -c",
         "clean": "gulp clean",
+        "impact": "impact master",
         "start": "node server.js",
-        "test:impact": "node test/impact master",
         "test": "nyc gulp",
         "coverage": "nyc report --reporter=text-lcov | coveralls"
     },
@@ -42,7 +43,6 @@
         "dedent": "0.7.0",
         "del": "3.0.0",
         "eslint-config-futagozaryuu": "5",
-        "glob": "7.1.3",
         "gulp-eslint": "5.0.0",
         "mocha": "5.2.0",
         "nyc": "13.1.0",
diff --git a/tools/impact/README.md b/tools/impact/README.md
new file mode 100644
index 0000000..14ffc69
--- /dev/null
+++ b/tools/impact/README.md
@@ -0,0 +1,8 @@
+This directory contains a tool used on the PEG.js repository that measures the impact of two git commits on a number of generated parsers, extracting the benchmark speeds and generated parser sizes, comparing the results of each commit against the other before finally displaying the overall results in the console.
+
+From the root of the repository:
+
+```sh
+yarn impact <commit>
+yarn impact <commit_before> <commit_after>
+```
diff --git a/test/impact b/tools/impact/index.js
similarity index 86%
rename from test/impact
rename to tools/impact/index.js
index 1d85614..5388286 100644
--- a/test/impact
+++ b/tools/impact/index.js
@@ -5,7 +5,7 @@
 // speed and size. Makes sense to use only on PEG.js git repository checkout.
 //
 
-/* eslint prefer-const: 0 */
+/* eslint-disable no-mixed-operators, prefer-const */
 
 "use strict";
 
@@ -18,7 +18,7 @@ const glob = require( "glob" );
 
 // Current Working Directory
 
-const cwd = path.join( __dirname, ".." );
+const cwd = path.join( __dirname, "..", ".." );
 if ( process.cwd() !== cwd ) process.chdir( cwd );
 
 // Execution Files
@@ -35,8 +35,8 @@ function binfile( ...files ) {
 
 }
 
-let PEGJS_BIN = binfile( "packages/pegjs/bin/peg.js", "bin/peg.js", "bin/pegjs" );
-let BENCHMARK_BIN = binfile( "test/benchmark/run", "benchmark/run" );
+const PEGJS_BIN = binfile( "packages/pegjs/bin/peg.js", "bin/peg.js", "bin/pegjs" );
+const BENCHMARK_BIN = binfile( "test/benchmark/run", "benchmark/run" );
 
 // Utils
 
@@ -46,6 +46,12 @@ function echo( message ) {
 
 }
 
+function print_empty_line() {
+
+    console.log( " " );
+
+}
+
 function exec( command ) {
 
     return child_process.execSync( command, { encoding: "utf8" } );
@@ -121,6 +127,7 @@ if ( argv.length === 1 ) {
 
 } else {
 
+    print_empty_line();
     console.log( dedent`
 
         Usage:
@@ -132,6 +139,7 @@ if ( argv.length === 1 ) {
         speed and size. Makes sense to use only on PEG.js Git repository checkout.
 
     ` );
+    print_empty_line();
     process.exit( 1 );
 
 }
@@ -141,21 +149,24 @@ if ( argv.length === 1 ) {
 const branch = exec( "git rev-parse --abbrev-ref HEAD" );
 let speed1, size1, speed2, size2;
 
+print_empty_line();
+
 echo( `Measuring commit ${ commit_before }...` );
 prepare( commit_before );
 speed1 = measureSpeed();
 size1 = measureSize();
-echo( " OK" + os.EOL );
+echo( " done." + os.EOL );
 
 echo( `Measuring commit ${ commit_after }...` );
 prepare( commit_after );
 speed2 = measureSpeed();
 size2 = measureSize();
-echo( " OK" + os.EOL );
+echo( " done." + os.EOL );
 
 // Finish
 
 prepare( branch );
+print_empty_line();
 
 console.log( dedent`
 
@@ -173,7 +184,8 @@ console.log( dedent`
     After:      ${ size2 } b
     Difference: ${ difference( size1, size2 ) }%
 
-    - Measured by /test/impact with Node.js ${ process.version }
+    - Measured by /tools/impact with Node.js ${ process.version }
     - Your system: ${ os.type() } ${ os.release() } ${ os.arch() }.
 
 ` );
+print_empty_line();
diff --git a/tools/impact/package.json b/tools/impact/package.json
new file mode 100644
index 0000000..8bad388
--- /dev/null
+++ b/tools/impact/package.json
@@ -0,0 +1,10 @@
+{
+    "name": "impact",
+    "version": "2.1.0",
+    "private": true,
+    "bin": "index.js",
+    "dependencies": {
+        "dedent": "0.7.0",
+        "glob": "7.1.3"
+    }
+}