diff --git a/copyparty/web/browser.css b/copyparty/web/browser.css
index 2ede6e63..2f4f2033 100644
--- a/copyparty/web/browser.css
+++ b/copyparty/web/browser.css
@@ -204,6 +204,9 @@ a, #files tbody div a:last-child {
 	color: #f4c;
 	border-bottom: 1px solid rgba(255,68,204,0.6);
 }
+#repl {
+	padding: .33em;
+}
 #files tbody a.play {
 	color: #e70;
 	padding: .2em;
diff --git a/copyparty/web/browser.html b/copyparty/web/browser.html
index cefd0ec1..66b649b4 100644
--- a/copyparty/web/browser.html
+++ b/copyparty/web/browser.html
@@ -113,6 +113,8 @@
 	<div id="epi" class="logue">{{ logues[1] }}</div>
 
 	<h2><a href="/?h">control-panel</a></h2>
+	
+	<a href="#" id="repl">π</a>
 
 </div>
 
diff --git a/copyparty/web/md.css b/copyparty/web/md.css
index 501264cc..d7b48e1b 100644
--- a/copyparty/web/md.css
+++ b/copyparty/web/md.css
@@ -8,6 +8,14 @@ html, body {
 	font-family: sans-serif;
 	line-height: 1.5em;
 }
+#repl {
+	position: absolute;
+	top: 0;
+	right: .2em;
+	border: none;
+	color: inherit;
+	background: none;
+}
 #mtw {
 	display: none;
 }
@@ -506,6 +514,9 @@ blink {
 		border-bottom: .07em solid #4ac;
 		padding: 0 .3em;
 	}
+	#repl {
+		display: none;
+	}
 	#toc>ul {
 		border-left: .1em solid #84c4dd;
 	}
diff --git a/copyparty/web/md.html b/copyparty/web/md.html
index d1e72f32..fbb548b2 100644
--- a/copyparty/web/md.html
+++ b/copyparty/web/md.html
@@ -45,6 +45,7 @@
 		</div>
 		<div id="mp"></div>
 	</div>
+	<a href="#" id="repl">π</a>
 	
 	{%- if edit %}
 	<div id="helpbox">
diff --git a/copyparty/web/mde.css b/copyparty/web/mde.css
index d146e8eb..b0508c2f 100644
--- a/copyparty/web/mde.css
+++ b/copyparty/web/mde.css
@@ -22,6 +22,15 @@ html, body {
 	bottom: auto;
 	top: 1.4em;
 }
+#repl {
+	position: absolute;
+	top: 0;
+	right: .5em;
+	border: none;
+	color: inherit;
+	background: none;
+	text-decoration: none;
+}
 #mn {
 	font-weight: normal;
 	margin: 1.3em 0 .7em 1em;
diff --git a/copyparty/web/mde.html b/copyparty/web/mde.html
index 5170865f..20c9fc72 100644
--- a/copyparty/web/mde.html
+++ b/copyparty/web/mde.html
@@ -21,6 +21,7 @@
 			<textarea id="mt" style="display:none" autocomplete="off">{{ md }}</textarea>
 		</div>
 	</div>
+	<a href="#" id="repl">π</a>
 	<script>
 
 var last_modified = {{ lastmod }};
diff --git a/copyparty/web/splash.css b/copyparty/web/splash.css
index e42787b2..c46d5640 100644
--- a/copyparty/web/splash.css
+++ b/copyparty/web/splash.css
@@ -29,6 +29,11 @@ a {
 	border-radius: .2em;
 	padding: .2em .8em;
 }
+#repl {
+	background: none;
+	color: inherit;
+	padding: 0;
+}
 table {
 	border-collapse: collapse;
 }
diff --git a/copyparty/web/splash.html b/copyparty/web/splash.html
index be5e22e7..d28f702e 100644
--- a/copyparty/web/splash.html
+++ b/copyparty/web/splash.html
@@ -7,6 +7,7 @@
     <meta http-equiv="X-UA-Compatible" content="IE=edge">
     <meta name="viewport" content="width=device-width, initial-scale=0.8">
     <link rel="stylesheet" media="screen" href="/.cpr/splash.css?_={{ ts }}">
+    <link rel="stylesheet" media="screen" href="/.cpr/ui.css?_={{ ts }}">
 </head>
 
 <body>
@@ -66,11 +67,13 @@
             </form>
         </ul>
     </div>
+	<a href="#" id="repl">π</a>
     <script>
 
 if (localStorage.getItem('lightmode') != 1)
     document.documentElement.setAttribute("class", "dark");
 
 </script>
+<script src="/.cpr/util.js?_={{ ts }}"></script>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/copyparty/web/ui.css b/copyparty/web/ui.css
index 447c3ac5..4c7aca08 100644
--- a/copyparty/web/ui.css
+++ b/copyparty/web/ui.css
@@ -107,6 +107,7 @@ html {
 	padding: 1.5em 2em;
 	border-width: .5em 0;
 }
+#modalc code,
 #tt code {
 	background: #3c3c3c;
 	padding: .1em .3em;
@@ -125,6 +126,7 @@ html.light #tt,
 html.light #toast {
 	box-shadow: 0 .3em 1em rgba(0,0,0,0.4);
 }
+#modalc code,
 html.light #tt code {
 	background: #060;
 	color: #fff;
@@ -207,6 +209,8 @@ html.light #tt em {
 }
 #modali {
 	display: block;
+	background: #fff;
+	color: #000;
 	width: calc(100% - 1.25em);
     margin: 1em -.1em 0 -.1em;
 	padding: .5em;
diff --git a/copyparty/web/util.js b/copyparty/web/util.js
index ecdfdaeb..4ded878f 100644
--- a/copyparty/web/util.js
+++ b/copyparty/web/util.js
@@ -892,3 +892,24 @@ function winpopup(txt) {
         body: 'msg=' + uricom_enc(Date.now() + ', ' + txt)
     });
 }
+
+
+function repl(e) {
+    ev(e);
+    modal.prompt('js repl (prefix with <code>,</code> to allow raise)', 'var v=Object.keys(localStorage); v.sort(); JSON.stringify(v)', function (cmd) {
+        if (!cmd)
+            return toast.inf(3, 'eval aborted');
+
+        if (cmd.startsWith(','))
+            return modal.alert(esc(eval(cmd.slice(1)) + ''))
+
+        try {
+            modal.alert(esc(eval(cmd) + ''));
+        }
+        catch (ex) {
+            modal.alert('<h6>exception</h6>' + esc(ex + ''));
+        }
+    });
+}
+if (ebi('repl'))
+    ebi('repl').onclick = repl;
