diff --git a/docs/changelog.rst b/docs/changelog.rst
index ff8af6854..47250e892 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -46,6 +46,9 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 
 - Double clicking on empty tab bar area now opens a new tab (:iss:`3201`)
 
+- kitty @ ls: Show only environment variables that are different for each
+  window, by default.
+
 - When passing a directory or a non-executable file as the program to run to
   kitty opens it with the shell or by parsing the shebang, instead of just failing.
 
diff --git a/kitty/rc/ls.py b/kitty/rc/ls.py
index 85d51e387..d2b6f3ed2 100644
--- a/kitty/rc/ls.py
+++ b/kitty/rc/ls.py
@@ -3,7 +3,7 @@
 # License: GPLv3 Copyright: 2020, Kovid Goyal <kovid at kovidgoyal.net>
 
 import json
-from typing import Any, Dict, Optional
+from typing import Any, Dict, List, Optional, Set, Tuple
 
 from kitty.constants import appname
 
@@ -15,7 +15,7 @@ from .base import (
 
 class LS(RemoteCommand):
     '''
-    No payload
+    all_env_vars: Whether to send all environment variables for ever window rather than just differing ones
     '''
 
     short_desc = 'List all tabs/windows'
@@ -28,10 +28,16 @@ class LS(RemoteCommand):
         ' running the command inside a kitty window, that window can be identified by the :italic:`is_self` parameter.\n\n'
         'You can use these criteria to select windows/tabs for the other commands.'
     )
+    options_spec = '''\
+--all-env-vars
+type=bool-set
+Show all environment variables in output not just differing ones.
+'''
+
     argspec = ''
 
     def message_to_kitty(self, global_opts: RCOptions, opts: Any, args: ArgsType) -> PayloadType:
-        pass
+        return {'all_env_vars': opts.all_env_vars}
 
     def response_from_kitty(self, boss: Boss, window: Optional[Window], payload_get: PayloadGetType) -> ResponseType:
 
@@ -47,6 +53,24 @@ class LS(RemoteCommand):
         finally:
             if window is not None:
                 window.serialize_callback = orig_callback
+        if not payload_get('all_env_vars'):
+            all_env_blocks: List[Dict[str, str]] = []
+            common_env_vars: Set[Tuple[str, str]] = set()
+            for osw in data:
+                for tab in osw.get('tabs', ()):
+                    for w in tab.get('windows', ()):
+                        env: Dict[str, str] = w.get('env', {})
+                        frozen_env = set(env.items())
+                        if all_env_blocks:
+                            common_env_vars &= frozen_env
+                        else:
+                            common_env_vars = frozen_env
+                        all_env_blocks.append(env)
+            if common_env_vars and len(all_env_blocks) > 1:
+                remove_env_vars = {k for k, v in common_env_vars}
+                for env in all_env_blocks:
+                    for r in remove_env_vars:
+                        env.pop(r, None)
         return json.dumps(data, indent=2, sort_keys=True)