diff --git a/web/src/ui/JSONView.css b/web/src/ui/JSONView.css
new file mode 100644
index 0000000..0cb4724
--- /dev/null
+++ b/web/src/ui/JSONView.css
@@ -0,0 +1,36 @@
+pre.json-view {
+	white-space: wrap;
+	overflow-wrap: anywhere;
+	margin: 0;
+
+	ul, ol {
+		margin: 0;
+
+		> li {
+			list-style-type: none;
+		}
+	}
+
+	span.json-collapsed {
+		user-select: none;
+	}
+
+	button {
+		padding: 0 .25rem;
+	}
+
+	/* If the screen is wide enough, make line-wrapped strings aligned after the object key */
+	@media screen and (min-width: 800px) {
+		li.json-object-entry:has(> span.json-comma-container > span.json-string) {
+			display: flex;
+
+			span.json-object-key {
+				white-space: nowrap;
+			}
+
+			span.json-object-entry-colon {
+				white-space: pre;
+			}
+		}
+	}
+}
diff --git a/web/src/ui/JSONView.tsx b/web/src/ui/JSONView.tsx
new file mode 100644
index 0000000..8bd165a
--- /dev/null
+++ b/web/src/ui/JSONView.tsx
@@ -0,0 +1,120 @@
+// gomuks - A Matrix client written in Go.
+// Copyright (C) 2024 Tulir Asokan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+import { useReducer } from "react"
+import "./JSONView.css"
+
+interface JSONViewProps {
+	data: unknown
+}
+
+interface JSONViewPropsWithKey extends JSONViewProps {
+	objectKey?: string
+	trailingComma?: boolean
+	noCollapse?: boolean
+}
+
+function renderJSONString(data: string, styleClass: string = "s2") {
+	return <span className={`json-string ${styleClass}`}>{JSON.stringify(data)}</span>
+}
+
+function renderJSONValue(data: unknown, collapsed: boolean) {
+	switch (typeof data) {
+	case "object":
+		if (data === null) {
+			return <span className="json-null kc">null</span>
+		} else if (Array.isArray(data)) {
+			if (data.length === 0) {
+				return null
+			} else if (collapsed) {
+				return <span className="json-collapsed">…</span>
+			}
+			return <ol className="json-array-children">
+				{data.map((item, i) =>
+					<li key={i} className="json-array-entry"><JSONValueWithKey data={item}/></li>)}
+			</ol>
+		} else {
+			const entries = Object.entries(data)
+			if (entries.length === 0) {
+				return null
+			} else if (collapsed) {
+				return <span className="json-collapsed">…</span>
+			}
+			return <ul className="json-object-children">
+				{entries.map(([key, value], index, arr) =>
+					<li key={key} className="json-object-entry">
+						<JSONValueWithKey data={value} objectKey={key} trailingComma={index < arr.length - 1}/>
+					</li>)}
+			</ul>
+		}
+	case "string":
+		return renderJSONString(data)
+	case "number":
+		return <span className="json-number mf">{data}</span>
+	case "boolean":
+		return <span className="json-boolean kc">{data ? "true" : "false"}</span>
+	default:
+		return <span className="json-unknown">undefined</span>
+	}
+}
+
+function JSONValueWithKey({ data, objectKey, trailingComma, noCollapse }: JSONViewPropsWithKey) {
+	const [collapsed, toggleCollapsed] = useReducer(collapsed => !collapsed, false)
+	const renderedKey = objectKey
+		? <span className="json-object-key">
+			{renderJSONString(objectKey, "nt")}
+			<span className="json-object-entry-colon p">: </span>
+		</span>
+		: null
+	const renderedSuffix = trailingComma
+		? <span className="json-object-comma p">,</span>
+		: null
+	const collapseButton = noCollapse ? null :
+		<button onClick={toggleCollapsed} title={collapsed ? "Expand" : "Collapse"}>
+			{collapsed ? "+" : "-"}
+		</button>
+	if (Array.isArray(data)) {
+		return <>
+			{renderedKey}
+			{collapseButton}
+			<span className="json-array-bracket p">[</span>
+			{renderJSONValue(data, collapsed)}
+			<span className="json-array-bracket p">]</span>
+			{renderedSuffix}
+		</>
+	} else if (data !== null && typeof data === "object") {
+		return <>
+			{renderedKey}
+			{collapseButton}
+			<span className="json-object-brace p">{"{"}</span>
+			{renderJSONValue(data, collapsed)}
+			<span className="json-object-brace p">{"}"}</span>
+			{renderedSuffix}
+		</>
+	}
+	return <>
+		{renderedKey}
+		<span className="json-comma-container">
+			{renderJSONValue(data, collapsed)}
+			{renderedSuffix}
+		</span>
+	</>
+}
+
+export default function JSONView({ data }: JSONViewProps) {
+	return <pre className="json-view chroma">
+		<JSONValueWithKey data={data} noCollapse={true} />
+	</pre>
+}
diff --git a/web/src/ui/timeline/menu/ViewSourceModal.tsx b/web/src/ui/timeline/menu/ViewSourceModal.tsx
index fd20fbc..69da420 100644
--- a/web/src/ui/timeline/menu/ViewSourceModal.tsx
+++ b/web/src/ui/timeline/menu/ViewSourceModal.tsx
@@ -14,6 +14,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 import { MemDBEvent } from "@/api/types"
+import JSONView from "../../JSONView.tsx"
 
 interface ViewSourceModalProps {
 	evt: MemDBEvent
@@ -21,9 +22,7 @@ interface ViewSourceModalProps {
 
 const ViewSourceModal = ({ evt }: ViewSourceModalProps) => {
 	return <div className="view-source-modal">
-		<pre>
-			{JSON.stringify(evt, null, "  ")}
-		</pre>
+		<JSONView data={evt} />
 	</div>
 }
 
diff --git a/web/src/ui/timeline/menu/index.css b/web/src/ui/timeline/menu/index.css
index 82ff616..ce727f3 100644
--- a/web/src/ui/timeline/menu/index.css
+++ b/web/src/ui/timeline/menu/index.css
@@ -56,12 +56,6 @@ div.view-source-modal {
 	background-color: white;
 	border-radius: 1rem;
 	padding: 1rem;
-
-	> pre {
-		margin: 0;
-		white-space: pre-wrap;
-		overflow-wrap: anywhere;
-	}
 }
 
 div.confirm-message-modal {