diff --git a/remarkbox/__init__.py b/remarkbox/__init__.py
index 863097f..a005a2a 100644
--- a/remarkbox/__init__.py
+++ b/remarkbox/__init__.py
@@ -524,8 +524,8 @@ def main(global_config, **settings):
     def add_node_order(request):
         return request.params.get("order", request.namespace.node_order)
 
-    def add_mathjax(request):
-        return "true" if request.namespace.mathjax else "false"
+    def add_katex(request):
+        return "true" if request.namespace.katex else "false"
 
     def add_theme_mode(request):
         """
@@ -604,7 +604,7 @@ def main(global_config, **settings):
     config.add_request_method(add_page_size, "page_size", reify=True)
     config.add_request_method(add_page_offset, "page_offset", reify=True)
     config.add_request_method(add_node_order, "node_order", reify=True)
-    config.add_request_method(add_mathjax, "mathjax", reify=True)
+    config.add_request_method(add_katex, "katex", reify=True)
     config.add_request_method(add_theme_mode, "theme_mode", reify=True)
 
     # all of the web application routes.
diff --git a/remarkbox/lib/notify.py b/remarkbox/lib/notify.py
index 751f91b..bf53d43 100644
--- a/remarkbox/lib/notify.py
+++ b/remarkbox/lib/notify.py
@@ -229,8 +229,8 @@ def send_immediate_notifications(request, notifications):
                 },
             )
             log.info(
-                "notification frequency=immediately email={}, count={}".format(
-                    notification.user.email,
+                "notification frequency=immediately username={}, count={}".format(
+                    notification.user.name,
                     notification.id,
                 )
             )
@@ -285,9 +285,9 @@ def send_digest_notifications(request, notification_dict, frequency="daily"):
             },
         )
         log.info(
-            "notification frequency={} email={}, count={}".format(
+            "notification frequency={} username={}, count={}".format(
                 frequency,
-                recipient_email,
+                user.name,
                 notifications_count,
             )
         )
diff --git a/remarkbox/lib/render.py b/remarkbox/lib/render.py
index 743d64a..2caf5b4 100644
--- a/remarkbox/lib/render.py
+++ b/remarkbox/lib/render.py
@@ -12,28 +12,14 @@ log = logging.getLogger(__name__)
 
 def remarkbox_tag_acl(namespace):
     """
-    Returns a tag_acl document, in this form:
+    Returns a tag_acl document for controlling allowed HTML tags.
 
-    tag_acl = {
-        "script": [
-            ("type", "math/tex; mode=display", "allow"),
-        ],
-    }
+    With KaTeX, math is rendered client-side from text delimiters,
+    so we don't need special script tag handling like we did with MathJax.
     """
     # defaultdict which assumes new keys are lists.
     tag_acl = default_tag_acl()
 
-    allow_mathjax_acl = ("type", "math/tex; mode=display", "allow")
-    deny_mathjax_acl  = ("type", "math/tex; mode=display", "deny")
-
-    log.info("Building remarkbox_tag_acl.")
-    mathjax_acl = deny_mathjax_acl
-    if namespace.mathjax:
-        log.info("This Namespace has Mathjax enabled.")
-        mathjax_acl = allow_mathjax_acl
-
-    tag_acl["script"].append(mathjax_acl)
-
     return tag_acl
 
 
@@ -45,14 +31,15 @@ def make_cleaner_from_namespace(namespace):
     )
     # add some properties onto the cleaner object.
     cleaner.link_protection = namespace.link_protection
-    cleaner.mathjax = namespace.mathjax
+    cleaner.katex = namespace.katex
     cleaner.whitelist_domains.append(namespace.name)
     cleaner.absolute_domain = namespace.name
     return cleaner
 
 
 def markdown_to_html(data, namespace=None):
-    raw_html = markdown_to_raw_html(data, extra_extensions=["mdx_math"])
+    # No special math extension needed - KaTeX auto-render handles $ delimiters client-side
+    raw_html = markdown_to_raw_html(data)
     if namespace:
         cleaner = make_cleaner_from_namespace(namespace)
     else:
diff --git a/remarkbox/lib/sanitize_html.py b/remarkbox/lib/sanitize_html.py
index cc5dea3..56c2657 100644
--- a/remarkbox/lib/sanitize_html.py
+++ b/remarkbox/lib/sanitize_html.py
@@ -30,22 +30,7 @@ def default_cleaner(tag_acl=None):
     We use BeautifulSoup to conditionally whitelist or blacklist
     tags based on tag attr_name and attr_value pairs.
 
-    For example, this will whitelist Mathjax script tags:
-
-    tag_acl = {
-        "script": [
-            ("type", "math/tex; mode=display", "allow"),
-        ],
-    }
-
-    While this example will blacklist Mathjax script tags:
-
-    tag_acl = {
-        "script": [
-            ("type", "math/tex; mode=display", "deny"),
-        ],
-    }
-
+    tag_acl allows controlling which tags are allowed based on attributes.
     """
     if tag_acl is None:
         tag_acl = {}
diff --git a/remarkbox/models/namespace.py b/remarkbox/models/namespace.py
index a19107f..9f654b3 100644
--- a/remarkbox/models/namespace.py
+++ b/remarkbox/models/namespace.py
@@ -53,7 +53,7 @@ PROTECTED_ATTRIBUTES = {
     "hide_unverified": False,
     "hide_unless_approved": False,
     "hide_powered_by": False,
-    "mathjax": False,
+    "katex": False,
     "link_protection": False,
     "ignore_query_string": False,
     "reverse_order": False,
@@ -96,8 +96,8 @@ class Namespace(RBase, Base):
     hide_powered_by = Column(Boolean, default=False)
     # should the list of root nodes in this namespace be public or hidden?
     public = Column(Boolean, default=False)
-    # should we enable MathJax?
-    mathjax = Column(Boolean, default=False)
+    # should we enable KaTeX for math rendering?
+    katex = Column(Boolean, default=False)
     # should we enable Link Protection to prevent comments from having links?
     link_protection = Column(Boolean, default=False)
     # check this box if the external site does _not_ use
diff --git a/remarkbox/scripts/alembic/versions/7ad8508e50de_rename_mathjax_to_katex.py b/remarkbox/scripts/alembic/versions/7ad8508e50de_rename_mathjax_to_katex.py
new file mode 100644
index 0000000..0c65c95
--- /dev/null
+++ b/remarkbox/scripts/alembic/versions/7ad8508e50de_rename_mathjax_to_katex.py
@@ -0,0 +1,30 @@
+"""Add katex column in rb_namespace
+
+Revision ID: 7ad8508e50de
+Revises: b8f3c9d4e5a1
+Create Date: 2025-01-10 00:00:00.000000
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = "7ad8508e50de"
+down_revision = "b8f3c9d4e5a1"
+branch_labels = None
+depends_on = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    # Add new katex column with default OFF
+    op.add_column("rb_namespace", sa.Column("katex", sa.Boolean(), server_default=sa.false()))
+
+    # Turn katex ON for any namespace that had mathjax ON
+    op.execute("UPDATE rb_namespace SET katex = 1 WHERE mathjax = 1")
+
+
+def downgrade():
+    # Copy katex values back to mathjax
+    # Note: SQLite doesn't support DROP COLUMN, so we just sync the data back
+    op.execute("UPDATE rb_namespace SET mathjax = katex")
diff --git a/remarkbox/static/js/custom.js b/remarkbox/static/js/custom.js
index ab28d8a..51b6e2b 100644
--- a/remarkbox/static/js/custom.js
+++ b/remarkbox/static/js/custom.js
@@ -2,7 +2,7 @@
 // previewTimer must live outside the functions.
 var previewTimer = null;
 
-function previewAjax(textarea, div, show_raw = false, mathjax = false){
+function previewAjax(textarea, div, show_raw = false, katex = false){
     // set div to raw textarea while waiting for remote Markdown rendering.
     if (show_raw) {
 	// bust HTML tags like <script> to prevent running evil code.
@@ -14,12 +14,12 @@ function previewAjax(textarea, div, show_raw = false, mathjax = false){
         clearTimeout(previewTimer);
     }
     previewTimer = setTimeout(
-        function() { sendPreview( textarea, div, mathjax ); },
+        function() { sendPreview( textarea, div, katex ); },
 	800
     );
 }
 
-function sendPreview(textarea, div, mathjax=false){
+function sendPreview(textarea, div, katex=false){
     $.ajaxSetup ({
         cache: false
     });
@@ -29,10 +29,17 @@ function sendPreview(textarea, div, mathjax=false){
 
     $( '#' + div ).load( url, params );
 
-    if (mathjax) {
+    if (katex) {
         setTimeout(function(){
-            // hack: block MathJax rerender for 50ms, give div chance to load.
-            MathJax.Hub.Queue(["Typeset",MathJax.Hub,div]);
+            // Give div chance to load before rendering math
+            if (typeof renderMathInElement !== 'undefined') {
+                renderMathInElement(document.getElementById(div), {
+                    delimiters: [
+                        {left: '$$', right: '$$', display: true},
+                        {left: '$', right: '$', display: false}
+                    ]
+                });
+            }
         }, 100);
     }
 }
diff --git a/remarkbox/templates/namespace-settings.j2 b/remarkbox/templates/namespace-settings.j2
index 1f4420e..a6dd8e1 100644
--- a/remarkbox/templates/namespace-settings.j2
+++ b/remarkbox/templates/namespace-settings.j2
@@ -59,9 +59,9 @@ If checked, disable infinite nesting and limit to only a depth of 2.
 If checked, both <code>example.com/1</code> and <code>example.com/1?a=2</code> will load the same thread because <code>a=2</code> is ignored.
 <br>
 <br>
-<label>Enable MathJax:</label>
-<input type="checkbox" name="mathjax-checkbox" id="mathjax-checkbox" {% if request.namespace.mathjax %}checked{% endif %}></input>
-If checked, allow beautiful math equations with <a href="https://www.mathjax.org/" target="_blank" rel="nofollow">MathJax</a> <span class="status">(could introduce slowness)</span>
+<label>Enable KaTeX:</label>
+<input type="checkbox" name="katex-checkbox" id="katex-checkbox" {% if request.namespace.katex %}checked{% endif %}></input>
+If checked, allow beautiful math equations with <a href="https://katex.org/" target="_blank" rel="nofollow">KaTeX</a> <span class="status">(fast math rendering)</span>
 <br>
 <code>$$E = mc^2$$</code>
 <br>
diff --git a/remarkbox/templates/snippets/create.j2 b/remarkbox/templates/snippets/create.j2
index a4cff25..6733c03 100644
--- a/remarkbox/templates/snippets/create.j2
+++ b/remarkbox/templates/snippets/create.j2
@@ -11,7 +11,7 @@
         name        = "thread_data"
         id          = "thread_data_textarea"
         class       = "common-textarea"
-        onkeyup     = "previewAjax( 'thread_data_textarea', 'preview', show_raw=true, mathjax={{ request.mathjax }} )"
+        onkeyup     = "previewAjax( 'thread_data_textarea', 'preview', show_raw=true, katex={{ request.katex }} )"
         placeholder = "What do you want to say? markdown"
         required></textarea>
 
diff --git a/remarkbox/templates/snippets/forms.j2 b/remarkbox/templates/snippets/forms.j2
index 1c65b95..fca0cfb 100644
--- a/remarkbox/templates/snippets/forms.j2
+++ b/remarkbox/templates/snippets/forms.j2
@@ -18,7 +18,7 @@
         name        = "thread_data"
         id          = "textarea-{{ node.id }}"
         class       = "common-textarea"
-        onkeyup     = "previewAjax( 'textarea-{{ node.id }}', 'preview-{{ node.id }}', show_raw=true, mathjax={{ request.mathjax }} )"
+        onkeyup     = "previewAjax( 'textarea-{{ node.id }}', 'preview-{{ node.id }}', show_raw=true, katex={{ request.katex }} )"
         placeholder = "{% if request.namespace.placeholder_text %}{{ request.namespace.placeholder_text }}{% else %}What do you want to say? markdown{% endif %}"
         required></textarea>
 
@@ -60,7 +60,7 @@
         name        = "thread_data"
         id          = "edit-textarea-{{ node.id }}"
         class       = "common-textarea textarea_edit"
-        onkeyup     = "previewAjax( 'edit-textarea-{{ node.id }}', 'node-data-{{ node.id }}', show_raw=false, mathjax={{ request.mathjax }} )"
+        onkeyup     = "previewAjax( 'edit-textarea-{{ node.id }}', 'node-data-{{ node.id }}', show_raw=false, katex={{ request.katex }} )"
         placeholder = "{% if request.namespace.placeholder_text %}{{ request.namespace.placeholder_text }}{% else %}What do you want to say? markdown{% endif %}"
         required>{{ node.data }}</textarea>
 
diff --git a/remarkbox/templates/snippets/javascript-includes.j2 b/remarkbox/templates/snippets/javascript-includes.j2
index 4dd19bb..b42b5a7 100644
--- a/remarkbox/templates/snippets/javascript-includes.j2
+++ b/remarkbox/templates/snippets/javascript-includes.j2
@@ -17,13 +17,18 @@
     gtag('config', '{{ request.namespace.google_analytics_id }}');
   </script>
 {%- endif %}
-{% if request.namespace and request.namespace.mathjax %}
-  <!-- references:
-    * https://docs.mathjax.org/en/v2.7-latest/safe-mode.html
-    * reference https://docs.mathjax.org/en/v2.7-latest/start.html#using-a-content-delivery-network-cdn
-  -->
-  <script type="text/javascript" async
-    src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.7/MathJax.js?config=TeX-MML-AM_CHTML,Safe">
+{% if request.namespace and request.namespace.katex %}
+  <!-- KaTeX CSS and JS -->
+  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/katex.min.css" integrity="sha384-n8MVd4RsNIU0tAv4ct0nTaAbDJwPJzDEaqSD1odI+WdtXRGWt2kTvGFasHpSy3SV" crossorigin="anonymous">
+  <script defer src="https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/katex.min.js" integrity="sha384-XjKyOOlGwcjNTAIQHIpgOno0Hl1YQqzUOEleOLALmuqehneUG+vnGctmUb0ZY0l8" crossorigin="anonymous"></script>
+  <!-- KaTeX auto-render extension -->
+  <script defer src="https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/contrib/auto-render.min.js" integrity="sha384-+VBxd3r6XgURycqtZ117nYw44OOcIax56Z4dCRWbxyPt0Koah1uHoK0o4+/RRE05" crossorigin="anonymous"
+    onload="renderMathInElement(document.body, {
+      delimiters: [
+        {left: '$$', right: '$$', display: true},
+        {left: '$', right: '$', display: false}
+      ]
+    });">
   </script>
 {%- endif %}
 {%- include 'google-analytics.j2' %}
diff --git a/remarkbox/tests/test_models.py b/remarkbox/tests/test_models.py
index b5ffda9..2ee6acd 100644
--- a/remarkbox/tests/test_models.py
+++ b/remarkbox/tests/test_models.py
@@ -138,20 +138,20 @@ class TestNamespace(unittest.TestCase):
         self.namespace.subscription_type = "production"
         self.namespace.link_protection = True
         self.namespace.hide_powered_by = True
-        self.namespace.mathjax = True
+        self.namespace.katex = True
         self.assertTrue(self.namespace.link_protection)
         self.assertTrue(self.namespace.hide_powered_by)
-        self.assertTrue(self.namespace.mathjax)
+        self.assertTrue(self.namespace.katex)
         self.assertFalse(self.namespace.memoized_attr_protection)
 
     def test_namespace_development_custom_settings(self):
         self.namespace.subscription_type = "development"
         self.namespace.link_protection = True
         self.namespace.hide_powered_by = True
-        self.namespace.mathjax = True
+        self.namespace.katex = True
         self.assertFalse(self.namespace.link_protection)
         self.assertFalse(self.namespace.hide_powered_by)
-        self.assertFalse(self.namespace.mathjax)
+        self.assertFalse(self.namespace.katex)
         self.assertTrue(self.namespace.memoized_attr_protection)
 
     def test_namespace_simulate_expired_subscription(self):
@@ -159,10 +159,10 @@ class TestNamespace(unittest.TestCase):
         self.namespace.subscription_type = "production"
         self.namespace.link_protection = True
         self.namespace.hide_powered_by = True
-        self.namespace.mathjax = True
+        self.namespace.katex = True
         self.assertTrue(self.namespace.link_protection)
         self.assertTrue(self.namespace.hide_powered_by)
-        self.assertTrue(self.namespace.mathjax)
+        self.assertTrue(self.namespace.katex)
 
         # next the namespace subscription expires with custom settings.
         self.namespace.subscription_type = "development"
@@ -170,7 +170,7 @@ class TestNamespace(unittest.TestCase):
         self.assertTrue(self.namespace.memoized_attr_protection)
         self.assertFalse(self.namespace.link_protection)
         self.assertFalse(self.namespace.hide_powered_by)
-        self.assertFalse(self.namespace.mathjax)
+        self.assertFalse(self.namespace.katex)
 
         # finally the namespace subscription is renewed with custom settings.
         self.namespace.subscription_type = "production"
@@ -178,7 +178,7 @@ class TestNamespace(unittest.TestCase):
         self.assertFalse(self.namespace.memoized_attr_protection)
         self.assertTrue(self.namespace.link_protection)
         self.assertTrue(self.namespace.hide_powered_by)
-        self.assertTrue(self.namespace.mathjax)
+        self.assertTrue(self.namespace.katex)
 
 class TestNamespaceRequest(unittest.TestCase):
 
diff --git a/remarkbox/tests/test_render.py b/remarkbox/tests/test_render.py
index 0091618..a8eaea1 100644
--- a/remarkbox/tests/test_render.py
+++ b/remarkbox/tests/test_render.py
@@ -49,36 +49,26 @@ class TestRenderMarkdown(unittest.TestCase):
     def test_make_cleaner_from_custom_namespace(self):
         namespace = Namespace("russell.ballestrini.net")
         namespace.subscription_type = "production"
-        namespace.mathjax = True
+        namespace.katex = True
         namespace.link_protection = True
         cleaner = make_cleaner_from_namespace(namespace)
         self.assertTrue(cleaner.link_protection)
-        self.assertIn("script", cleaner.tags)
         self.assertEqual("russell.ballestrini.net", cleaner.absolute_domain)
         self.assertIn("russell.ballestrini.net", cleaner.whitelist_domains)
 
-    def test_mathjax_enabled_and_disabled(self):
-        raw_html = markdown_to_raw_html(SAMPLE_MARKDOWN)
+    def test_katex_enabled_and_disabled(self):
         namespace = Namespace("russell.ballestrini.net")
         namespace.subscription_type = "production"
 
-        # test mathjax enabled.
-        namespace.mathjax = True
+        # test katex enabled.
+        namespace.katex = True
         cleaner = make_cleaner_from_namespace(namespace)
-        self.assertTrue(cleaner.mathjax)
-        clean_html = clean_raw_html(raw_html, cleaner)
-        self.assertIn(
-            '<script type="math/tex; mode=display">y=x^2</script>', clean_html
-        )
+        self.assertTrue(cleaner.katex)
 
-        # test mathjax disabled.
-        namespace.mathjax = False
+        # test katex disabled.
+        namespace.katex = False
         cleaner = make_cleaner_from_namespace(namespace)
-        self.assertFalse(cleaner.mathjax)
-        clean_html = clean_raw_html(raw_html, cleaner)
-        self.assertNotIn(
-            '<script type="math/tex; mode=display">y=x^2</script>', clean_html
-        )
+        self.assertFalse(cleaner.katex)
 
     def test_link_protection_enabled(self):
         raw_html = markdown_to_raw_html(SAMPLE_MARKDOWN)
diff --git a/remarkbox/views/authenticated/authenticated.py b/remarkbox/views/authenticated/authenticated.py
index 39067e4..52bf78e 100644
--- a/remarkbox/views/authenticated/authenticated.py
+++ b/remarkbox/views/authenticated/authenticated.py
@@ -63,7 +63,7 @@ def namespace_settings(request):
         link_protection_checkbox = p.get("link-protection-checkbox", "off")
         reverse_order_checkbox = p.get("reverse-order-checkbox", "off")
         group_conversations_checkbox = p.get("group-conversations-checkbox", "off")
-        mathjax_checkbox = p.get("mathjax-checkbox", "off")
+        katex_checkbox = p.get("katex-checkbox", "off")
         ignore_query_string_checkbox = p.get("ignore-query-string-checkbox", "off")
         hide_powered_by_checkbox = p.get("hide-powered-by-checkbox", "off")
 
@@ -71,7 +71,7 @@ def namespace_settings(request):
         link_protection = checkbox_to_bool(link_protection_checkbox)
         reverse_order = checkbox_to_bool(reverse_order_checkbox)
         group_conversations = checkbox_to_bool(group_conversations_checkbox)
-        mathjax = checkbox_to_bool(mathjax_checkbox)
+        katex = checkbox_to_bool(katex_checkbox)
         ignore_query_string = checkbox_to_bool(ignore_query_string_checkbox)
         hide_powered_by = checkbox_to_bool(hide_powered_by_checkbox)
 
@@ -195,10 +195,10 @@ def namespace_settings(request):
                 )
             )
 
-        if mathjax != request.namespace.mathjax:
-            request.namespace.mathjax = mathjax
+        if katex != request.namespace.katex:
+            request.namespace.katex = katex
             request.session.flash(
-                ("You turned {} MathJax".format(mathjax_checkbox), "success")
+                ("You turned {} KaTeX".format(katex_checkbox), "success")
             )
 
         request.dbsession.add(request.namespace)