diff --git a/tools/clog-builder.lisp b/tools/clog-builder.lisp
index 12fbf90..12ac4a8 100644
--- a/tools/clog-builder.lisp
+++ b/tools/clog-builder.lisp
@@ -1519,6 +1519,8 @@ of controls and double click to select control."
          (btn-rndr  (create-img tool-bar :alt-text "render"   :url-src img-btn-rndr  :class btn-class))
          (btn-save  (create-img tool-bar :alt-text "save"     :url-src img-btn-save  :class btn-class))
          (btn-load  (create-img tool-bar :alt-text "load"     :url-src img-btn-load  :class btn-class))
+         (cbox      (create-form-element tool-bar :checkbox :class "w3-margin-left"))
+         (cbox-lbl  (create-label tool-bar :content " auto render" :label-for cbox :class "w3-black"))
          (content   (center-panel box))
          (in-simulation    nil)
          (undo-chain       nil)
@@ -1527,6 +1529,7 @@ of controls and double click to select control."
          (render-file-name "")
          (panel-id  (html-id content)))
     (setf (background-color (top-panel box)) :black)
+    (setf (checkedp cbox) t)
     (setf (advisory-title btn-copy) "copy")
     (setf (advisory-title btn-paste) "paste")
     (setf (advisory-title btn-cut) "cut")
@@ -1537,6 +1540,8 @@ of controls and double click to select control."
     (setf (advisory-title btn-rndr) "render to lisp - shift-click render as...")
     (setf (advisory-title btn-save) "save - shift-click save as...")
     (setf (advisory-title btn-load) "load")
+    (setf (advisory-title cbox) "when checked render on save")
+    (setf (advisory-title cbox-lbl) "when checked render on save")
     (setf (height btn-copy) "12px")
     (setf (height btn-paste) "12px")
     (setf (height btn-cut) "12px")
@@ -1723,12 +1728,24 @@ of controls and double click to select control."
                                                                                         (pathname-name file-name)))
                                                          (add-class btn-save "w3-animate-top")
                                                          (save-panel fname content panel-id (bottom-panel box))
+                                                         (when (checkedp cbox)
+                                                           (add-class btn-rndr "w3-animate-top")
+                                                           (write-file (render-clog-code content (bottom-panel box))
+                                                                       render-file-name)
+                                                           (sleep .5)
+                                                           (remove-class btn-rndr "w3-animate-top"))
                                                          (sleep .5)
                                                          (remove-class btn-save "w3-animate-top"))
                                                        :initial-filename file-name)))
                                 (t
                                  (add-class btn-save "w3-animate-top")
                                  (save-panel file-name content panel-id (bottom-panel box))
+                                 (when (checkedp cbox)
+                                   (add-class btn-rndr "w3-animate-top")
+                                   (write-file (render-clog-code content (bottom-panel box))
+                                               render-file-name)
+                                   (sleep .5)
+                                   (remove-class btn-rndr "w3-animate-top"))
                                  (sleep .5)
                                  (remove-class btn-save "w3-animate-top")))))
     (set-on-click btn-test