diff --git a/web/src/components/events/EventContainer.tsx b/web/src/components/events/EventContainer.tsx
index 8429d16..31a86c7 100644
--- a/web/src/components/events/EventContainer.tsx
+++ b/web/src/components/events/EventContainer.tsx
@@ -1,6 +1,11 @@
 "use client";
 
-import { useQueryState, parseAsStringLiteral, parseAsString } from "nuqs";
+import {
+  useQueryState,
+  parseAsStringLiteral,
+  parseAsString,
+  parseAsArrayOf,
+} from "nuqs";
 import { EventItem } from "./EventItem";
 import { EventFilter, EventFilterExplained } from "./EventFilter";
 import {
@@ -44,12 +49,15 @@ export const EventContainer = ({
     "mode",
     parseAsStringLiteral(["list", "calendar"]).withDefault("list")
   );
-  const [category, setCategory] = useQueryState("category", parseAsString);
+  const [categories, setCategories] = useQueryState(
+    "category",
+    parseAsArrayOf(parseAsString, ",")
+  );
   const [organizer, setOrganizer] = useQueryState("organizer", parseAsString);
   const [venue, setVenue] = useQueryState("venue", parseAsString);
 
   const resetFilters = () => {
-    setCategory(null);
+    setCategories(null);
     setOrganizer(null);
     setVenue(null);
   };
@@ -105,10 +113,10 @@ export const EventContainer = ({
     )
     .filter(
       (x) =>
-        !category ||
+        !categories ||
         x.categories
           .map((eventCategory) => eventCategory.slug)
-          .includes(category)
+          .filter((x) => categories.includes(x)).length !== 0
     )
     .filter(
       (x) =>
@@ -147,7 +155,7 @@ export const EventContainer = ({
             </button>
           </div>
           <div className={styles.filterButtons}>
-            {(category || organizer || venue) && (
+            {(categories || organizer || venue) && (
               <button onClick={onResetFilters} className="button tertiary">
                 <span>Vis alle</span>
                 <Icon type="noFilter" />
@@ -161,8 +169,8 @@ export const EventContainer = ({
         </div>
         <EventFilter
           eventCategories={filterableCategories}
-          setCategory={setCategory}
-          activeCategory={category}
+          setCategories={setCategories}
+          activeCategories={categories}
           eventOrganizers={filterableOrganizers}
           setOrganizer={setOrganizer}
           activeOrganizer={organizer}
@@ -173,7 +181,7 @@ export const EventContainer = ({
         />
         <EventFilterExplained
           eventCategories={filterableCategories}
-          activeCategory={category}
+          activeCategories={categories}
           eventOrganizers={filterableOrganizers}
           activeOrganizer={organizer}
           venues={filterableVenues}
@@ -188,9 +196,7 @@ export const EventContainer = ({
 
 const EventList = ({ events }: { events: EventFragment[] }) => {
   if (events.length === 0) {
-    return (
-      <div className={styles.noEvents}>Ingen kommende arrangementer.</div>
-    );
+    return <div className={styles.noEvents}>Ingen kommende arrangementer.</div>;
   }
   return (
     <ul className={styles.eventList}>
diff --git a/web/src/components/events/EventFilter.tsx b/web/src/components/events/EventFilter.tsx
index 362be5a..e46ac99 100644
--- a/web/src/components/events/EventFilter.tsx
+++ b/web/src/components/events/EventFilter.tsx
@@ -2,12 +2,12 @@ import { EventCategory, EventOrganizer } from "@/lib/event";
 
 import styles from "./eventFilter.module.scss";
 import { VenueFragment } from "@/gql/graphql";
-import { Icon } from "../general/Icon";
+import { formatHumanReadableList } from "@/lib/common";
 
 export const EventFilter = ({
   eventCategories,
-  setCategory,
-  activeCategory,
+  setCategories,
+  activeCategories,
   eventOrganizers,
   setOrganizer,
   activeOrganizer,
@@ -17,8 +17,8 @@ export const EventFilter = ({
   isVisible,
 }: {
   eventCategories: EventCategory[];
-  setCategory: (slug: string | null) => void;
-  activeCategory: string | null;
+  setCategories: (slug: string[] | null) => void;
+  activeCategories: string[] | null;
   eventOrganizers: EventOrganizer[];
   setOrganizer: (slug: string | null) => void;
   activeOrganizer: string | null;
@@ -35,6 +35,12 @@ export const EventFilter = ({
     const venue = e.target.value;
     setVenue(venue === "" ? null : venue);
   };
+  const toggleCategory = (category: string) => {
+    const newCategories = activeCategories?.includes(category)
+      ? activeCategories?.filter((x) => x !== category)
+      : [...(activeCategories ?? []), category];
+    setCategories(newCategories.length === 0 ? null : newCategories);
+  };
 
   return (
     <div className={styles.eventFilter} data-show={isVisible}>
@@ -48,12 +54,8 @@ export const EventFilter = ({
                 <li key={category.slug}>
                   <button
                     className="button toggler"
-                    data-active={activeCategory === category.slug}
-                    onClick={() =>
-                      setCategory(
-                        activeCategory === category.slug ? null : category.slug
-                      )
-                    }
+                    data-active={activeCategories?.includes(category.slug)}
+                    onClick={() => toggleCategory(category.slug)}
                   >
                     {category.name}
                   </button>
@@ -102,34 +104,38 @@ export const EventFilter = ({
 
 export const EventFilterExplained = ({
   eventCategories,
-  activeCategory,
+  activeCategories,
   eventOrganizers,
   activeOrganizer,
   venues,
   activeVenue,
 }: {
   eventCategories: EventCategory[];
-  activeCategory: string | null;
+  activeCategories: string[] | null;
   eventOrganizers: EventOrganizer[];
   activeOrganizer: string | null;
   venues: VenueFragment[];
   activeVenue: string | null;
 }) => {
-  const category =
-    activeCategory && eventCategories.find((x) => x.slug === activeCategory);
+  const categories = eventCategories.filter((x) =>
+    activeCategories?.includes(x.slug)
+  );
   const organizer =
     activeOrganizer && eventOrganizers.find((x) => x.slug === activeOrganizer);
   const venue = activeVenue && venues.find((x) => x.slug === activeVenue);
 
+  const categoryList = formatHumanReadableList(categories.map((x) => x.name));
+  const hasCategories = categoryList.length !== 0;
+
   let text = "";
-  if (category && organizer && venue) {
-    text = `${category.name} av ${organizer.name} ${venue.preposition} ${venue.title}`;
-  } else if (category && organizer) {
-    text = `${category.name} av ${organizer.name}`;
-  } else if (category && venue) {
-    text = `${category.name} ${venue.preposition} ${venue.title}`;
-  } else if (category) {
-    text = `${category.name}`;
+  if (hasCategories && organizer && venue) {
+    text = `${categoryList} av ${organizer.name} ${venue.preposition} ${venue.title}`;
+  } else if (hasCategories && organizer) {
+    text = `${categoryList} av ${organizer.name}`;
+  } else if (hasCategories && venue) {
+    text = `${categoryList} ${venue.preposition} ${venue.title}`;
+  } else if (hasCategories) {
+    text = `${categoryList}`;
   } else if (organizer && venue) {
     text = `Arrangeres av ${organizer.name} ${venue.preposition} ${venue.title}`;
   } else if (organizer) {
diff --git a/web/src/lib/common.ts b/web/src/lib/common.ts
index 72265af..6111bed 100644
--- a/web/src/lib/common.ts
+++ b/web/src/lib/common.ts
@@ -76,6 +76,21 @@ export function formatNorwegianPhoneNumber(phone: string): string {
   return phone;
 }
 
+export function formatHumanReadableList(array: (string | number)[]): string {
+  const length = array.length;
+
+  if (length === 0) {
+    return "";
+  }
+  if (length === 1) {
+    return array[0].toString();
+  }
+  if (length === 2) {
+    return array.join(" og ");
+  }
+  return array.slice(0, -1).join(", ") + " og " + array[length - 1];
+}
+
 const OneLevelOfBlocksFragmentDefinition = graphql(`
   fragment OneLevelOfBlocks on StreamFieldInterface {
     id