diff --git a/apps/browser-extension/entrypoints/content/chatgpt.ts b/apps/browser-extension/entrypoints/content/chatgpt.ts
index 444e3ac87..cf7a30028 100644
--- a/apps/browser-extension/entrypoints/content/chatgpt.ts
+++ b/apps/browser-extension/entrypoints/content/chatgpt.ts
@@ -17,6 +17,7 @@ import {
 	acceptMemorySuggestion,
 	clearMemorySuggestion,
 	hasAcceptedSupermemoryContext,
+	serializeMemoriesForDataset,
 	setMemoryMarkerStatus,
 	showLoadingSuggestion,
 	showMarkerPopover,
@@ -212,7 +213,9 @@ async function getRelatedMemoriesForChatGPT(actionSource: string) {
 					memoryLength: memoryText.length,
 				})
 
-				iconElement.dataset.memoriesData = String(response.data)
+				iconElement.dataset.memoriesData = serializeMemoriesForDataset(
+					response.data,
+				)
 
 				if (isAutoSearch) {
 					setMemoryMarkerStatus(iconElement, "found")
diff --git a/apps/browser-extension/entrypoints/content/claude.ts b/apps/browser-extension/entrypoints/content/claude.ts
index 7bff4dfc2..f31c2bb60 100644
--- a/apps/browser-extension/entrypoints/content/claude.ts
+++ b/apps/browser-extension/entrypoints/content/claude.ts
@@ -17,6 +17,7 @@ import {
 	acceptMemorySuggestion,
 	clearMemorySuggestion,
 	hasAcceptedSupermemoryContext,
+	serializeMemoriesForDataset,
 	setMemoryMarkerStatus,
 	showLoadingSuggestion,
 	showMarkerPopover,
@@ -459,7 +460,9 @@ async function getRelatedMemoriesForClaude(actionSource: string) {
 					memoryLength: memoryText.length,
 				})
 
-				iconElement.dataset.memoriesData = String(response.data)
+				iconElement.dataset.memoriesData = serializeMemoriesForDataset(
+					response.data,
+				)
 
 				if (isAutoSearch) {
 					setMemoryMarkerStatus(iconElement, "found")
diff --git a/apps/browser-extension/entrypoints/content/gemini.ts b/apps/browser-extension/entrypoints/content/gemini.ts
index 6ece78dff..f819d3d6f 100644
--- a/apps/browser-extension/entrypoints/content/gemini.ts
+++ b/apps/browser-extension/entrypoints/content/gemini.ts
@@ -17,6 +17,7 @@ import {
 	acceptMemorySuggestion,
 	clearMemorySuggestion,
 	hasAcceptedSupermemoryContext,
+	serializeMemoriesForDataset,
 	setMemoryMarkerStatus,
 	showLoadingSuggestion,
 	showMarkerPopover,
@@ -417,7 +418,9 @@ async function getRelatedMemoriesForGemini(actionSource: string) {
 
 		if (response?.success && response?.data && input) {
 			const memoryText = showMemorySuggestion("gemini", input, response.data)
-			iconElement.dataset.memoriesData = String(response.data)
+			iconElement.dataset.memoriesData = serializeMemoriesForDataset(
+				response.data,
+			)
 			iconElement.dataset.supermemories = memoryText
 			if (isAutoSearch) {
 				setMemoryMarkerStatus(iconElement, "found")
diff --git a/apps/browser-extension/entrypoints/content/memory-suggestion.ts b/apps/browser-extension/entrypoints/content/memory-suggestion.ts
index 1722e71ef..18861fe30 100644
--- a/apps/browser-extension/entrypoints/content/memory-suggestion.ts
+++ b/apps/browser-extension/entrypoints/content/memory-suggestion.ts
@@ -12,6 +12,39 @@ export function buildSupermemoryText(memories: unknown): string {
 	return `\n\n${SUPERMEMORY_PREFIX} ${memoryText}`
 }
 
+function normalizeMemoryList(memories: unknown): string[] {
+	const list = Array.isArray(memories)
+		? memories
+		: memories == null
+			? []
+			: [memories]
+	return list
+		.map((memory) => (typeof memory === "string" ? memory : String(memory)))
+		.map((memory) => memory.trim())
+		.filter((memory) => memory.length > 0)
+}
+
+export function serializeMemoriesForDataset(memories: unknown): string {
+	const list = normalizeMemoryList(memories)
+	return list.length > 0 ? JSON.stringify(list) : ""
+}
+
+export function parseMemoriesFromDataset(
+	raw: string | null | undefined,
+): string[] {
+	if (!raw) return []
+	try {
+		const parsed = JSON.parse(raw)
+		if (Array.isArray(parsed)) return normalizeMemoryList(parsed)
+	} catch {
+		// Not JSON — fall through to the legacy delimiter split.
+	}
+	return raw
+		.split(/[,\n]/)
+		.map((memory) => memory.trim())
+		.filter((memory) => memory.length > 0 && memory !== ",")
+}
+
 export function showMemorySuggestion(
 	platform: string,
 	input: SuggestionInput,
@@ -305,10 +338,7 @@ export function showMarkerPopover(
 			color: rgba(255, 255, 255, 0.76);
 		`
 
-		memories
-			.split(/[,\n]/)
-			.map((memory) => memory.trim())
-			.filter((memory) => memory.length > 0 && memory !== ",")
+		parseMemoriesFromDataset(memories)
 			.slice(0, 5)
 			.forEach((memory) => {
 				const item = document.createElement("div")
diff --git a/apps/browser-extension/entrypoints/content/t3.ts b/apps/browser-extension/entrypoints/content/t3.ts
index 66a11235c..39a05f03e 100644
--- a/apps/browser-extension/entrypoints/content/t3.ts
+++ b/apps/browser-extension/entrypoints/content/t3.ts
@@ -10,6 +10,10 @@ import {
 	autoCapturePromptsEnabled,
 } from "../../utils/storage"
 import { createT3InputBarElement, DOMUtils } from "../../utils/ui-components"
+import {
+	parseMemoriesFromDataset,
+	serializeMemoriesForDataset,
+} from "./memory-suggestion"
 
 let t3DebounceTimeout: NodeJS.Timeout | null = null
 let t3RouteObserver: MutationObserver | null = null
@@ -233,7 +237,9 @@ async function getRelatedMemoriesForT3(actionSource: string) {
 			if (textareaElement) {
 				textareaElement.dataset.supermemories = `\n\nSupermemories of user (only for the reference): ${response.data}`
 
-				iconElement.dataset.memoriesData = response.data
+				iconElement.dataset.memoriesData = serializeMemoriesForDataset(
+					response.data,
+				)
 
 				updateT3IconFeedback("Included Memories", iconElement)
 			} else {
@@ -329,11 +335,9 @@ function updateT3IconFeedback(
 			overflow-y: auto;
 		`
 
-		const memoriesText = iconElement.dataset.memoriesData || ""
-		const individualMemories = memoriesText
-			.split(/[,\n]/)
-			.map((memory) => memory.trim())
-			.filter((memory) => memory.length > 0 && memory !== ",")
+		const individualMemories = parseMemoriesFromDataset(
+			iconElement.dataset.memoriesData,
+		)
 
 		individualMemories.forEach((memory, index) => {
 			const memoryItem = document.createElement("div")
@@ -421,15 +425,17 @@ function updateT3IconFeedback(
 					content.removeChild(memoryItem)
 				}
 
-				const currentMemories = (iconElement.dataset.memoriesData || "")
-					.split(/[,\n]/)
-					.map((memory) => memory.trim())
-					.filter((memory) => memory.length > 0 && memory !== ",")
+				const currentMemories = parseMemoriesFromDataset(
+					iconElement.dataset.memoriesData,
+				)
 				currentMemories.splice(index, 1)
 
+				// Injected prompt keeps its existing joined-text form; the popup's
+				// own data is stored as JSON so comma-bearing memories stay intact.
 				const updatedMemories = currentMemories.join(" ,")
 
-				iconElement.dataset.memoriesData = updatedMemories
+				iconElement.dataset.memoriesData =
+					serializeMemoriesForDataset(currentMemories)
 
 				const textareaElement =
 					(document.querySelector("textarea") as HTMLTextAreaElement) ||