diff --git a/README.md b/README.md
index 5aeb777..c280c55 100644
--- a/README.md
+++ b/README.md
@@ -77,6 +77,12 @@ or in case of custom environment with basic auth credentials
 diffy project:compare PROJECT_ID prod custom --env2Url="https://custom.example.com" --env2User="user" --env2Pass="password"
 ```
 
+or with existing screenshots
+
+```shell script
+diffy project:compare PROJECT_ID existing existing --screenshot1=100 --screenshot2=101
+```
+
 Allowed environments are: prod, stage, dev, custom (long options: production, staging, development).
 
 #### Update project(s)
diff --git a/src/Commands/ProjectCommand.php b/src/Commands/ProjectCommand.php
index cb425f8..d2b9144 100644
--- a/src/Commands/ProjectCommand.php
+++ b/src/Commands/ProjectCommand.php
@@ -4,7 +4,9 @@
 
 use Diffy\Diff;
 use Diffy\Diffy;
+use Diffy\InvalidArgumentsException;
 use Diffy\Project;
+use Diffy\Screenshot;
 use DiffyCli\Config;
 use GuzzleHttp\Exception\InvalidArgumentException;
 use Robo\Tasks;
@@ -57,7 +59,7 @@ private function isValidJsonConfig(string $configurationPath): array
      * @param string $env2      Second environment to compare
      * @param array  $options
      *
-     * @throws \Diffy\InvalidArgumentsException
+     * @throws InvalidArgumentsException
      *
      * @option env1Url Url of the first environment if custom environment
      * @option env1User Basic auth user for env1Url
@@ -68,6 +70,8 @@ private function isValidJsonConfig(string $configurationPath): array
      * @option wait Wait for the diff to be completed
      * @option max-wait Maximum number of seconds to wait for the diff to be completed.
      * @option commit-sha GitHub commit SHA.
+     * @option screenshot1 First existing screenshot
+     * @option screenshot2 Second existing screenshot
      *
      * @usage project:compare 342 prod stage
      *   Compare production and stage environments.
@@ -81,8 +85,9 @@ public function createCompare(
         string $env1,
         string $env2,
         array $options = [
-            'wait' => false, 'max-wait' => 1200, 'commit-sha' => null, 'env1Url' => '', 'env1User' => null, 'env1Pass' => null,
-            'env2Url' => '', 'env2User' => null, 'env2Pass' => null, 'name' => ''
+            'wait' => false, 'max-wait' => 1200, 'commit-sha' => null, 'env1Url' => '', 'env1User' => null,
+            'env1Pass' => null, 'env2Url' => '', 'env2User' => null, 'env2Pass' => null, 'name' => '',
+            'screenshot1' => null, 'screenshot2' => null,
         ]
     ) {
         Diffy::setApiKey(Config::getConfig()['key']);
@@ -95,7 +100,7 @@ public function createCompare(
             'env1Pass' => $options['env1Pass'],
             'env2Url' => $options['env2Url'],
             'env2User' => $options['env2User'],
-            'env2Pass' => $options['env2Pass'],
+            'env2Pass' => $options['env2Pass']
         ];
 
         if (!empty($options['commit-sha']) && $options['commit-sha']) {
@@ -118,7 +123,29 @@ public function createCompare(
             $params['env2'] = 'stage';
         }
 
-        $diffId = Project::compare($projectId, $params);
+        if ($env1 === 'existing' || $env2 === 'existing') {
+            if ($env1 === 'existing' && empty($options['screenshot1'])) {
+                throw new InvalidArgumentsException('Set screenshot1 value');
+            } elseif ($env2 === 'existing' && empty($options['screenshot2'])) {
+                throw new InvalidArgumentsException('Set screenshot2 value');
+            }
+
+            if ($env1 === 'existing') {
+                $screenshot1 = $options['screenshot1'];
+            } else {
+                $screenshot1 = Screenshot::create($projectId, $env1);
+            }
+
+            if ($env2 === 'existing') {
+                $screenshot2 = $options['screenshot2'];
+            } else {
+                $screenshot2 = Screenshot::create($projectId, $env2);
+            }
+
+            $diffId = Diff::create($projectId, $screenshot1, $screenshot2, $options['name']);
+        } else {
+            $diffId = Project::compare($projectId, $params);
+        }
 
         if (!empty($options['name'])) {
             Diff::updateName($diffId, $options['name']);