diff --git a/README.md b/README.md
index d02dcc3..0937e2d 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@ A browser-based 3D editor, runtime and local MCP server for building interactive
 
 **Early prototype · 0.3.0.** This repository contains the engine, editor and build tools. Games and game assets are not included. The editor interface is currently in Russian.
 
-![Forma Engine editor with a primitive scene, hierarchy and component inspector](docs/screenshots/editor.png)
+![Forma Engine editor with a primitive scene, hierarchy and component inspector](docs/screenshots/editor.jpg)
 
 The screenshot shows a temporary scene made with the editor's primitives. New projects start empty.
 
diff --git a/docs/VALIDATION.md b/docs/VALIDATION.md
index 3a8a72e..e79132d 100644
--- a/docs/VALIDATION.md
+++ b/docs/VALIDATION.md
@@ -11,7 +11,7 @@ Coverage includes empty-project creation, atomic/revision-checked transactions,
 
 Games, game assets, project-specific players/HUDs and hosted-service metadata were removed. Browser bundles are generated locally and excluded from source control. New projects have no bundled assets, scripts or entities.
 
-The local editor was opened in a desktop browser. Visual checks covered the initial empty scene, creating cube/sphere/cylinder primitives, editing transforms, restoring the scene after a reload, and focusing/zooming the viewport. A real editor screenshot is included at [screenshots/editor.png](screenshots/editor.png). The temporary preview project is excluded from Git.
+The local editor was opened in a desktop browser. Visual checks covered the initial empty scene, creating cube/sphere/cylinder primitives, editing transforms, restoring the scene after a reload, and focusing/zooming the viewport. A real editor screenshot is included at [screenshots/editor.jpg](screenshots/editor.jpg). The temporary preview project is excluded from Git.
 
 GitHub Actions repeats the clean install, build, type check and test suite on Node.js 22. The build runs before integration tests because they read the generated editor and player bundles.
 
diff --git a/docs/screenshots/editor.png b/docs/screenshots/editor.jpg
similarity index 100%
rename from docs/screenshots/editor.png
rename to docs/screenshots/editor.jpg