diff --git a/src/devtools.html b/src/devtools.html
index 9defea07e1a06..dd0fe8cb55cdc 100644
--- a/src/devtools.html
+++ b/src/devtools.html
@@ -23,6 +23,8 @@
 <div class="body">
     <p>
         <button id="console-clear" class="iconifiable" type="button"><span class="fa-icon">trash-o</span></button>
+        <button id="console-fold" class="iconifiable" type="button"><span class="fa-icon">double-angle-up</span></button>
+        <button id="console-unfold" class="iconifiable" type="button"><span class="fa-icon fa-icon-vflipped">double-angle-up</span></button>
         <button id="snfe-dump" type="button">SNFE: Dump</button>
         <button id="snfe-benchmark" type="button" disabled>SNFE: Benchmark</button>
         <button id="cfe-dump" type="button">CFE: Dump</button>
diff --git a/src/js/devtools.js b/src/js/devtools.js
index 892ee625b8cd3..8e3fa74c9160d 100644
--- a/src/js/devtools.js
+++ b/src/js/devtools.js
@@ -25,6 +25,10 @@
 
 /******************************************************************************/
 
+const reFoldable = /^ *(?=\+ \S)/;
+
+/******************************************************************************/
+
 CodeMirror.registerGlobalHelper(
     'fold',
     'ubo-dump',
@@ -34,7 +38,7 @@ CodeMirror.registerGlobalHelper(
         const startLine = cm.getLine(startLineNo);
         let endLineNo = startLineNo;
         let endLine = startLine;
-        const match = /^ *(?=\+ \S)/.exec(startLine);
+        const match = reFoldable.exec(startLine);
         if ( match === null ) { return; }
         const foldCandidate = '  ' + match[0];
         const lastLineNo = cm.lastLine();
@@ -83,6 +87,50 @@ uDom.nodeFromId('console-clear').addEventListener('click', ( ) => {
         cmEditor.setValue('');
 });
 
+uDom.nodeFromId('console-fold').addEventListener('click', ( ) => {
+    const unfolded = [];
+    let maxUnfolded = -1;
+    cmEditor.eachLine(handle => {
+        const match = reFoldable.exec(handle.text);
+        if ( match === null ) { return; }
+        const depth = match[0].length;
+        const line = handle.lineNo();
+        const isFolded = cmEditor.isFolded({ line, ch: handle.text.length });
+        if ( isFolded === true ) { return; }
+        unfolded.push({ line, depth });
+        maxUnfolded = Math.max(maxUnfolded, depth);
+    });
+    if ( maxUnfolded === -1 ) { return; }
+    cmEditor.startOperation();
+    for ( const details of unfolded ) {
+        if ( details.depth !== maxUnfolded ) { continue; }
+        cmEditor.foldCode(details.line, null, 'fold');
+    }
+    cmEditor.endOperation();
+});
+
+uDom.nodeFromId('console-unfold').addEventListener('click', ( ) => {
+    const folded = [];
+    let minFolded = Number.MAX_SAFE_INTEGER;
+    cmEditor.eachLine(handle => {
+        const match = reFoldable.exec(handle.text);
+        if ( match === null ) { return; }
+        const depth = match[0].length;
+        const line = handle.lineNo();
+        const isFolded = cmEditor.isFolded({ line, ch: handle.text.length });
+        if ( isFolded !== true ) { return; }
+        folded.push({ line, depth });
+        minFolded = Math.min(minFolded, depth);
+    });
+    if ( minFolded === Number.MAX_SAFE_INTEGER ) { return; }
+    cmEditor.startOperation();
+    for ( const details of folded ) {
+        if ( details.depth !== minFolded ) { continue; }
+        cmEditor.foldCode(details.line, null, 'unfold');
+    }
+    cmEditor.endOperation();
+});
+
 uDom.nodeFromId('snfe-dump').addEventListener('click', ev => {
         const button = ev.target;
         button.setAttribute('disabled', '');