diff --git a/viz/index.html b/viz/index.html
index 98c2d7cd79..2400f99c3b 100644
--- a/viz/index.html
+++ b/viz/index.html
@@ -12,7 +12,8 @@
   <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.10.0/styles/default.min.css">
   <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.10.0/highlight.min.js"></script>
   <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.10.0/languages/python.min.js"></script>
-  <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.10.0/languages/c.min.js"></script>
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.10.0/languages/cpp.min.js"></script>
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/dompurify/1.0.3/purify.min.js"></script>
   <link rel="stylesheet" href="https://unpkg.com/@highlightjs/cdn-assets@11.10.0/styles/tokyo-night-dark.min.css" />
   <style>
   * {
@@ -67,11 +68,6 @@
     fill: #4a4b57;
     stroke-width: 1.4px;
   }
-  #arrowhead {
-   stroke: blue;
-   fill: blue;
-   stroke-width: 1.5px;
-  }
   .graph {
     width: 70%;
     position: relative;
@@ -120,7 +116,8 @@
     top: 0;
     bottom: 0;
     width: 20px;
-    cursor: w-resize;
+    height: 100%;
+    cursor: col-resize;
     background-color: transparent;
   }
   .rewrite-list {
@@ -178,6 +175,23 @@
     <div class="container metadata"></div>
   </div>
   <script>
+  // extra definitions for UOps
+  hljs.registerLanguage("python", (hljs) => ({
+    ...hljs.getLanguage("python"),
+    case_insensitive: false,
+    contains: [
+      { begin: 'dtypes\\.[a-zA-Z_][a-zA-Z0-9_-]*(\\.[a-zA-Z_][a-zA-Z0-9_-]*)*' + '(?=[.\\s\\n[:,(])', className: "type" },
+      { begin: 'dtypes\\.[a-zA-Z_][a-zA-Z0-9_-].vec*' + '(?=[.\\s\\n[:,(])', className: "type" },
+      { begin: '[a-zA-Z_][a-zA-Z0-9_-]*\\.[a-zA-Z_][a-zA-Z0-9_-]*' + '(?=[.\\s\\n[:,()])',  className: "operator" },
+      { begin: '[A-Z][a-zA-Z0-9_]*(?=\\()', className: "section", ignoreEnd: true },
+      ...hljs.getLanguage("python").contains,
+    ]
+  }));
+  // extra definitions for float4
+  hljs.registerLanguage("cpp", (hljs) => ({
+    ...hljs.getLanguage('cpp'),
+    contains: [{ begin: '\\b(?:float|half)[0-9]+\\b', className: 'type' }, ...hljs.getLanguage('cpp').contains]
+  }));
   function renderGraph(graph, additions) {
     const g = new dagreD3.graphlib.Graph({ compound: true }).setGraph({ rankdir: "LR" }).setDefaultEdgeLabel(function() { return {}; });
     g.setNode("addition", {label: "", clusterLabelPos: "top", style: additions.length !== 0 ? "fill: rgba(26, 27, 38, 0.5); rx: 8; ry: 8;" : "display: none;"});
@@ -220,7 +234,7 @@
   var expandKernel = false;
   async function main() {
     checkStatus();
-    // ** kernel list
+    // ***** LHS kernels list
     if (kernels == null) {
       kernels = await (await fetch("/kernels")).json();
       currentKernel = 0;
@@ -257,7 +271,7 @@
       }
       kernelList.appendChild(kernelUl);
     });
-    // ** uop graph
+    // ***** UOp graph
     cacheKey = `${currentKernel}-${currentUOp}`;
     if (cacheKey in cache) {
       ret = cache[cacheKey];
@@ -267,18 +281,20 @@
       cache[cacheKey] = ret;
     }
     renderGraph(ret[0].graphs[currentRewrite], ret[0].additions[currentRewrite]);
+    // ***** RHS metadata
     const metadata = document.querySelector(".container.metadata");
     metadata.innerHTML = "";
-    metadata.appendChild(Object.assign(document.createElement("div"), { id: "resize-handle" }));
     metadata.appendChild(Object.assign(document.createElement("pre"), { textContent: ret[0].loc }));
+    // ** resizer
+    metadata.appendChild(Object.assign(document.createElement("div"), { id: "resize-handle" }));
     const resizeHandle = document.getElementById("resize-handle");
-
     let startX;
     let containerWidth;
     let metadataWidth;
     resizeHandle.addEventListener("mousedown", (e) => {
       e.preventDefault();
       metadata.style.userSelect = "none";
+      document.documentElement.style.cursor = "col-resize";
       startX = e.clientX;
       containerWidth = document.querySelector(".main-container").getBoundingClientRect().width;
       metadataWidth = metadata.getBoundingClientRect().width;
@@ -296,17 +312,19 @@
     function stopResize(e) {
       document.documentElement.removeEventListener("mousemove", resize, false);
       document.documentElement.removeEventListener("mouseup", stopResize, false);
+      document.documentElement.style.cursor = "initial";
       metadata.style.userSelect = "initial";
     }
-
+    // ** code blocks
     ret[0].extra[currentRewrite].forEach((e, i) => {
       if (e.length == 0) return;
-      const pre = Object.assign(document.createElement("pre"), { innerHTML: `<code>${e}</code>`, className: "code-block language-python" });
+      const pre = Object.assign(document.createElement("pre"), { innerHTML: `<code>${DOMPurify.sanitize(e)}</code>`, className: "code-block language-python" });
       hljs.highlightElement(pre);
       metadata.appendChild(pre);
     })
     if (kernels[currentKernel].code !== "") {
-      const pre = Object.assign(document.createElement("pre"), { innerHTML: `<code>${kernels[currentKernel].code}</code>`, className: "code-block" });
+      const code = kernels[currentKernel].code.replaceAll("<", "&lt;").replaceAll(">", "&gt;");
+      const pre = Object.assign(document.createElement("pre"), { innerHTML: `<code>${DOMPurify.sanitize(code)}</code>`, className: "code-block language-cpp" });
       hljs.highlightElement(pre);
       metadata.appendChild(pre);
     }
@@ -326,7 +344,7 @@
             link = Object.assign(document.createElement("a"), { textContent: parts[parts.length-1]+"\n\n", href: "vscode://file"+parts.join("/"), style: "font-family: monospace; margin: 4px 0;" })
             div.appendChild(link);
             const pre = Object.assign(document.createElement("pre"), { className: "code-block wrap" });
-            pre.appendChild(Object.assign(document.createElement("code"), { textContent: pattern, className: "language-python" }));
+            pre.appendChild(Object.assign(document.createElement("code"), { textContent: DOMPurify.sanitize(pattern), className: "language-python" }));
             div.appendChild(pre);
             hljs.highlightElement(pre);
             metadata.appendChild(div);
@@ -343,7 +361,7 @@
         });
       })
     } else {
-      metadata.appendChild(Object.assign(document.createElement("p"), { textContent: "No rewrites" }));
+      metadata.appendChild(Object.assign(document.createElement("p"), { textContent: `No rewrites in ${ret[0].loc}.` }));
     }
   }
   document.addEventListener("keydown", async function(event) {
diff --git a/viz/serve.py b/viz/serve.py
index 93c3376ada..4cb6f26ed8 100755
--- a/viz/serve.py
+++ b/viz/serve.py
@@ -7,13 +7,16 @@ from urllib.parse import parse_qs, urlparse
 from http.server import HTTPServer, BaseHTTPRequestHandler
 from tinygrad import Device
 from tinygrad.helpers import Context, getenv, to_function_name
-from tinygrad.ops import TrackedRewriteContext, UOp
+from tinygrad.ops import TrackedRewriteContext, UOp, UOps
 from tinygrad.engine.graph import uops_colors, word_wrap
 from tinygrad.engine.realize import get_runner
 from tinygrad.engine.schedule import full_ast_rewrite
 
 # **** /graph - detailed UOp + rewrites
 
+# NOTE: UPats in ops.py are spec
+def graph_rewrites(ctx:TrackedRewriteContext): return [x for x in ctx.rewrites if x[2].location[0].split("/")[-1] != "ops.py"]
+
 @dataclass(frozen=True)
 class UOpRet:
   loc: str
@@ -28,16 +31,15 @@ class UOpRet:
     extra: List[List[str]] = [[str(ctx.sink)]]
     additions: List[List[int]] = [[]]
     seen_replaces: Dict[bytes, UOp] = {}
-    for i, (first, rewritten, pattern) in enumerate(ctx.rewrites):
-      if pattern.location[0].split("/")[-1] == "ops.py": continue
+    for i, (first, rewritten, pattern) in enumerate(graph_rewrites(ctx)):
       # first, rewrite this UOp with the current rewrite + all the seen rewrites before this
       seen_replaces[first.key] = rewritten
       new_sink = replace_uop(uops[-1], {**seen_replaces})
       # sanity check
       assert new_sink is not uops[-1], f"rewritten sink wasn't rewritten! {i}\n{new_sink}\n{uops[-1]}"
       # update ret data
-      additions.append([id(x) for x in rewritten.sparents])
-      diffs.append((str(pattern), pattern.location, list(difflib.unified_diff(str(first).splitlines(), str(rewritten).splitlines()))))
+      additions.append([id(x) for x in rewritten.sparents if x.op is not UOps.CONST])
+      diffs.append((pattern.printable(), pattern.location, list(difflib.unified_diff(str(first).splitlines(), str(rewritten).splitlines()))))
       uops.append(new_sink)
       extra.append([str(new_sink)])
     return UOpRet(ctx.loc, uops, diffs, extra, additions)
@@ -47,11 +49,14 @@ def uop_to_json(x:UOp) -> Dict[int, Tuple[str, str, List[int], str, str]]:
   assert isinstance(x, UOp)
   graph: Dict[int, Tuple[str, str, List[int], str, str]] = {}
   for u in x.sparents:
+    if u.op is UOps.CONST and u is not x: continue
     label = f"{str(u.op)[5:]}{(' '+word_wrap(str(u.arg).replace(':', ''))) if u.arg is not None else ''}\n{str(u.dtype)}"
+    for idx,x in enumerate(u.src):
+      if x.op is UOps.CONST: label += f"\nCONST{idx} {x.arg:g}"
     if getenv("WITH_SHAPE"):
       with contextlib.suppress(Exception): # if the UOp is indexed already it's fine
         if u.st is not None: label += f"\n{u.st.shape}"
-    graph[id(u)] = (label, str(u.dtype), [id(x) for x in u.src], str(u.arg), uops_colors.get(u.op, "#ffffff"))
+    graph[id(u)] = (label, str(u.dtype), [id(x) for x in u.src if x.op is not UOps.CONST], str(u.arg), uops_colors.get(u.op, "#ffffff"))
   return graph
 
 def replace_uop(base:UOp, replaces:Dict[bytes, UOp]) -> UOp:
@@ -68,7 +73,7 @@ class KernelRet:
   code: str
   ctxs: Dict[Tuple[str, bytes], TrackedRewriteContext]
   def to_json(self) -> Dict:
-    return {"name":self.name, "code":self.code, "ctxs":[x.loc for x in self.ctxs.values()]}
+    return {"name":self.name, "code":self.code, "ctxs":[f"{x.loc} - {len(graph_rewrites(x))}" for x in self.ctxs.values()]}
 
 def load_kernels(contexts:List[TrackedRewriteContext]) -> List[KernelRet]:
   ret: Dict[str, KernelRet] = {}
diff --git a/viz/test_viz.py b/viz/test_viz.py
index 9a0f8df5dd..ac482cc8ad 100644
--- a/viz/test_viz.py
+++ b/viz/test_viz.py
@@ -9,7 +9,7 @@ from tinygrad.dtype import dtypes, PtrDType
 from tinygrad.helpers import CI, Context, all_same, DEBUG, colored, getenv
 from tinygrad.codegen.uopgraph import constant_folder, devectorize, float4_folding
 from test.external.process_replay.helpers import print_diff
-from viz.serve import UOpRet, load_kernels
+from viz.serve import UOpRet, load_kernels, uop_to_json
 
 class TestViz(unittest.TestCase):
   def tearDown(self) -> None:
@@ -137,5 +137,19 @@ class TestViz(unittest.TestCase):
     schedule_ctxs = [x for x in kernels[1].ctxs.values() if x.loc.split("/")[-1].split(":")[0] == "schedule.py"]
     self.assertEqual(len(schedule_ctxs), 0)
 
+  def test_fold_const_nodes(self):
+    a = Tensor.empty(4, 4)+2
+    contexts.clear()
+    sink = a.schedule()[-1].ast
+    ret = uop_to_json(sink)
+    for v in ret.values(): print(v)
+    assert not any(v[0].startswith("CONST") for v in ret.values())
+    assert len([x for x in ret.values() if "CONST" in x[0]]) == 1
+
+  def test_no_fold_single_const(self):
+    node = UOp(UOps.CONST, dtypes.float, (), 1.0)
+    ret = uop_to_json(node)
+    assert len(ret) == 1
+
 if __name__ == "__main__":
   unittest.main()