diff --git a/cdhweb/context_processors.py b/cdhweb/context_processors.py
index 29bdc1c4..0ed3b322 100644
--- a/cdhweb/context_processors.py
+++ b/cdhweb/context_processors.py
@@ -2,7 +2,7 @@
 from django.templatetags.static import static
 from wagtail.models import Site
 
-from cdhweb.pages.utils import absolutize_url
+from cdhweb.pages.utils import get_default_preview_img_url
 
 
 def template_settings(request):
@@ -11,19 +11,10 @@ def template_settings(request):
 
     feature_flags = getattr(settings, "FEATURE_FLAGS", [])
 
-    #  default social preview image, relative to static url
-    if "purple-mode" in feature_flags:
-        default_preview_img = "img/alt-modes/purple/cdhlogo_square.png"
-    else:
-        default_preview_img = "images/cdhlogo_square.jpg"
-
     context_extras = {
         "SHOW_TEST_WARNING": getattr(settings, "SHOW_TEST_WARNING", False),
         "site": Site.find_for_request(request),
-        "default_preview_image": request.build_absolute_uri(
-            static(default_preview_img)
-        ),
-        # try using template tag import static tag and use here instead of join django utils static
+        "default_preview_image": get_default_preview_img_url(),
         # Include analytics based on settings.DEBUG or override in settings.py
         # Defaults to opposite of settings.DEBUG
         "INCLUDE_ANALYTICS": getattr(settings, "INCLUDE_ANALYTICS", not settings.DEBUG),
@@ -41,18 +32,12 @@ def favicon_path():
     """Determine which favicon to use based on any feature flags and test warning.
     Returns full local path, including static url.
     """
-    feature_flags = getattr(settings, "FEATURE_FLAGS", [])
-
-    base_path = ""
-    if "purple-mode" in feature_flags:
-        base_path = "img/alt-modes/purple/"
-
     icon_version = "favicon.ico"
     # use test favicon when test warning is enabled as another visual indicator
     if getattr(settings, "SHOW_TEST_WARNING", False):
         icon_version = "favicon-test.ico"
 
-    return "".join([settings.STATIC_URL, base_path, icon_version])
+    return static(icon_version)
 
 
 def show_test_warning(request):
diff --git a/cdhweb/pages/migrations/0061_purplemode_to_genericsetting.py b/cdhweb/pages/migrations/0061_purplemode_to_genericsetting.py
new file mode 100644
index 00000000..821d6304
--- /dev/null
+++ b/cdhweb/pages/migrations/0061_purplemode_to_genericsetting.py
@@ -0,0 +1,22 @@
+# Generated by Django 5.0.8 on 2024-09-03 00:35
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('cdhpages', '0060_alter_contentpage_body_alter_homepage_body_and_more'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='purplemode',
+            name='site',
+        ),
+        migrations.AlterField(
+            model_name='purplemode',
+            name='purple_mode',
+            field=models.BooleanField(default=False, help_text='\n            This will turn the site purple by transforming\n            all shades of cyan on the site into shades of\n            purple\n        '),
+        ),
+    ]
diff --git a/cdhweb/pages/mixin.py b/cdhweb/pages/mixin.py
index 1f8cac59..45aea1f7 100644
--- a/cdhweb/pages/mixin.py
+++ b/cdhweb/pages/mixin.py
@@ -10,7 +10,12 @@
 from wagtail.models import Page
 from wagtail.search import index
 
-from .utils import LengthOverrideWidget
+from .utils import (
+    LengthOverrideWidget,
+    absolutize_url,
+    get_default_preview_img_url,
+    get_first_of,
+)
 
 
 class HomePageHeroMixin(models.Model):
@@ -158,3 +163,17 @@ def sidebar_navigation(self):
 
     class Meta:
         abstract = True
+
+
+class OpenGraphMixin(models.Model):
+    class Meta:
+        abstract = True
+
+    @cached_property
+    def og_image_url(self):
+        image = get_first_of(self, "feed_image", "image", "hero_image")
+        if not image:
+            return get_default_preview_img_url()
+
+        rendition = image.get_rendition("fill-1200x627")
+        return absolutize_url(rendition.url)
diff --git a/cdhweb/pages/models.py b/cdhweb/pages/models.py
index 0025bc45..803581aa 100644
--- a/cdhweb/pages/models.py
+++ b/cdhweb/pages/models.py
@@ -3,17 +3,15 @@
 
 import bleach
 from django.apps import apps
-from django.conf import settings
 from django.core.exceptions import ValidationError
 from django.db import models
 from django.template.defaultfilters import striptags, truncatechars_html
-from django.utils.functional import cached_property
 from springkit.blocks import CTABlock, JumplinkableH2Block
 from springkit.models.mixins import JumplinksMixin
 from taggit.managers import TaggableManager
 from wagtail.admin.panels import FieldPanel, MultiFieldPanel
 from wagtail.blocks import RichTextBlock, StreamBlock, StructBlock, TextBlock
-from wagtail.contrib.settings.models import BaseSiteSetting, register_setting
+from wagtail.contrib.settings.models import BaseGenericSetting, register_setting
 from wagtail.documents.blocks import DocumentChooserBlock
 from wagtail.documents.models import AbstractDocument, DocumentQuerySet
 from wagtail.embeds.blocks import EmbedBlock
@@ -25,7 +23,7 @@
 from wagtail.snippets.models import register_snippet
 from wagtailcodeblock.blocks import CodeBlock
 
-from cdhweb.pages import snippets  # needed for import order
+from cdhweb.pages import snippets  # noqa needed for import order
 
 from .blocks.accordion_block import AccordionBlock
 from .blocks.article_index_block import ArticleTileBlock
@@ -42,7 +40,12 @@
 from .blocks.table_block import TableBlock
 from .blocks.tile_block import StandardTileBlock
 from .blocks.video_block import Video
-from .mixin import HomePageHeroMixin, SidebarNavigationMixin, StandardHeroMixin
+from .mixin import (
+    HomePageHeroMixin,
+    OpenGraphMixin,
+    SidebarNavigationMixin,
+    StandardHeroMixin,
+)
 
 #: common features for paragraph text
 PARAGRAPH_FEATURES = [
@@ -246,7 +249,7 @@ class LinkPage(Page):
     is_creatable = False
 
 
-class BasePage(Page):
+class BasePage(OpenGraphMixin, Page):
     """Abstract Page class from which all Wagtail page types are derived."""
 
     body = StreamField(
@@ -587,11 +590,14 @@ def clean_fields(self, exclude=None):
 
 
 @register_setting(icon="edit")
-class PurpleMode(BaseSiteSetting):
+class PurpleMode(BaseGenericSetting):
     purple_mode = models.BooleanField(
         default=False,
-        help_text="""This will turn the site purple 
-                                      by transforming all shades of cyan on the site into shades of purple""",
+        help_text="""
+            This will turn the site purple by transforming
+            all shades of cyan on the site into shades of
+            purple
+        """,
     )
 
     panels = [FieldPanel("purple_mode", icon="pick")]
diff --git a/cdhweb/pages/utils.py b/cdhweb/pages/utils.py
index 22f94399..e06e44e1 100644
--- a/cdhweb/pages/utils.py
+++ b/cdhweb/pages/utils.py
@@ -1,31 +1,28 @@
-from django.contrib.sites.models import Site
+from urllib.parse import urljoin
+from wagtail.models import Site
 from django.forms.widgets import TextInput
 
+from django.templatetags.static import static
 
-def absolutize_url(local_url):
+
+def absolutize_url(local_url, request=None):
     """Convert a local url to an absolute url, with scheme and server name,
     based on the current configured :class:`~django.contrib.sites.models.Site`.
 
     :param local_url: local url to be absolutized, e.g. something generated by
         :meth:`~django.core.urlresolvers.reverse`
     """
-    if local_url.startswith("https"):
+    if local_url.startswith("https://") or local_url.startswith("http://"):
         return local_url
 
     # add scheme and server (i.e., the http://example.com) based
-    # on the django Sites infrastructure.
-    root = Site.objects.get_current().domain
-    # but also add the http:// if necessary, since most sites docs
-    # suggest using just the domain name
-    # NOTE: this is problematic for dev/test sites without https
-    if not root.startswith("https"):
-        root = "https://" + root
-
-    # make sure there is no double slash between site url and local url
-    if local_url.startswith("/"):
-        root = root.rstrip("/")
+    # on the Wagtail request or default Site
+    site = Site.objects.order_by("is_default_site").first()
+    if request:
+        site = Site.find_for_request(request)
+    root = site.root_url
 
-    return root + local_url
+    return urljoin(root, local_url)
 
 
 class LengthOverrideWidget(TextInput):
@@ -55,3 +52,25 @@ def get_context(self, name, value, attrs):
         context = super().get_context(name, value, attrs)
         context["widget"]["attrs"]["maxlength"] = self.max_length
         return context
+
+
+def get_first_of(instance, *fields, default=None):
+    """
+    Return the first non empty value from fields on `instance` - or `default`
+    """
+    return next(
+        (value for field in fields if (value := getattr(instance, field, ""))), default
+    )
+
+
+def get_default_preview_img_url():
+    from cdhweb.pages.models import PurpleMode
+
+    #  default social preview image, relative to static url
+    purple_mode_setting = PurpleMode.load()
+    if purple_mode_setting.purple_mode:
+        default_preview_img = "images/alt-modes/purple/cdhlogo_square.png"
+    else:
+        default_preview_img = "images/cdhlogo_square.jpg"
+
+    return absolutize_url(static(default_preview_img))
diff --git a/cdhweb/pages/views.py b/cdhweb/pages/views.py
index e4a66bca..2f45f89b 100644
--- a/cdhweb/pages/views.py
+++ b/cdhweb/pages/views.py
@@ -74,7 +74,6 @@ def get_queryset(self):
         form = self.get_form()
 
         if not form.is_valid():
-            print(form.errors)
             return queryset.none()
 
         # get keyword query; support filters & phrase matching with double quotes
diff --git a/cdhweb/projects/models.py b/cdhweb/projects/models.py
index 971d93fd..8e14bd5f 100644
--- a/cdhweb/projects/models.py
+++ b/cdhweb/projects/models.py
@@ -5,15 +5,14 @@
 from django.utils import timezone
 from modelcluster.fields import ParentalKey, ParentalManyToManyField
 from modelcluster.models import ClusterableModel
-from wagtail import blocks
 from wagtail.admin.panels import FieldPanel, FieldRowPanel, InlinePanel, MultiFieldPanel
-from wagtail.fields import RichTextField, StreamField
+from wagtail.fields import StreamField
 from wagtail.models import Page, PageManager, PageQuerySet
 from wagtail.search import index
 from wagtailautocomplete.edit_handlers import AutocompletePanel
 
 from cdhweb.pages.blocks.accordion_block import ProjectAccordion
-from cdhweb.pages.mixin import StandardHeroMixin
+from cdhweb.pages.mixin import OpenGraphMixin, StandardHeroMixin
 from cdhweb.pages.models import BasePage, DateRange, LandingPage, LinkPage, RelatedLink
 from cdhweb.people.models import Person
 
@@ -80,7 +79,7 @@ def recent(self):
 ProjectManager = PageManager.from_queryset(ProjectQuerySet)
 
 
-class Project(BasePage, ClusterableModel, StandardHeroMixin):
+class Project(BasePage, OpenGraphMixin, ClusterableModel, StandardHeroMixin):
     """Page type for a CDH sponsored project or working group."""
 
     template = "projects/project_page.html"
diff --git a/docker-compose.yml b/docker-compose.yml
index 7868bab7..0f9fd116 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -42,7 +42,7 @@ services:
         volumes:
             - "./docker/database:/docker-entrypoint-initdb.d/:ro"
         environment:
-            WAGTAIL_SITE_HOSTNAME: "${SITE_HOSTNAME}"
+            WAGTAIL_SITE_HOSTNAME: "cdh.dev.springload.nz"
             WAGTAIL_SITE_PORT: "443"
             POSTGRES_DB: "cdhweb"
             POSTGRES_USER: "cdhweb"
diff --git a/templates/snippets/head_meta.html b/templates/snippets/head_meta.html
index 694268e2..b3072eba 100644
--- a/templates/snippets/head_meta.html
+++ b/templates/snippets/head_meta.html
@@ -1,5 +1,5 @@
 {% load static cdh_tags %}
-{% firstof preview_image page.get_url|url_to_icon_path default_preview_image as meta_preview_image %}
+{% firstof preview_image page.og_image_url default_preview_image as meta_preview_image_url %}
 {% firstof page_title page.seo_title page.title as meta_title %}
 {% autoescape off %}
 {% firstof page.get_plaintext_description page_intro.paragraph as meta_description %}
@@ -8,12 +8,11 @@
 {# html metadata #}
 {% if page.tags.exists %}<meta name="keywords" content="{{ page.tags.all|join:', ' }}"/>{% endif %}
 <meta name="description" content="{% firstof self.search_description self.intro|default:''|striptags self.body_excerpt|default:''|striptags|truncatewords:40 self.title %}">
-{# determine preview image: specified by page, cdh icon based on url, or default image #}
 {# open graph metadata #}
 <meta property="og:title" content="{{ meta_title }}" />
 <meta property="og:type" content="{{ opengraph_type|default:'website' }}" />
 <meta property="og:url" content="{{ request.build_absolute_uri }}" />
-<meta property="og:image" content="{{ meta_preview_image }}" />
+<meta property="og:image" content="{{ meta_preview_image_url }}" />
 {% if meta_description %}<meta property="og:description" content="{{ meta_description|striptags }}"/>{% endif %}
 <meta property="og:site_name" content="{{ site.root_page.seo_title }}"/>
 {# twitter card #}
@@ -21,5 +20,5 @@
 <meta name="twitter:site" content="@PrincetonDH" />
 <meta name="twitter:title" content="{{ meta_title }}"/>
 {% if meta_description %}<meta name="twitter:description" content="{{ meta_description|striptags }}"/>{% endif %}
-<meta name="twitter:image" content="{% firstof twitter_image meta_preview_image %}" />
+<meta name="twitter:image" content="{% firstof twitter_image meta_preview_image_url %}" />
 {% endautoescape %}