diff --git a/src/lib/components/chat/FileNav/FilePreview.svelte b/src/lib/components/chat/FileNav/FilePreview.svelte
index e2e52f6ed6..9f3527953d 100644
--- a/src/lib/components/chat/FileNav/FilePreview.svelte
+++ b/src/lib/components/chat/FileNav/FilePreview.svelte
@@ -1,6 +1,8 @@
 <script lang="ts">
 	import { getContext, onDestroy } from 'svelte';
 	import panzoom, { type PanZoom } from 'panzoom';
+	import { marked } from 'marked';
+	import DOMPurify from 'dompurify';
 	import Spinner from '../../common/Spinner.svelte';
 	import PDFViewer from '../../common/PDFViewer.svelte';
 	import Tooltip from '../../common/Tooltip.svelte';
@@ -16,6 +18,14 @@
 
 	export let onDownload: () => void = () => {};
 
+	const MD_EXTS = new Set(['md', 'markdown', 'mdx']);
+	$: isMarkdown = MD_EXTS.has(selectedFile?.split('.').pop()?.toLowerCase() ?? '');
+	$: renderedHtml = isMarkdown && fileContent ? DOMPurify.sanitize(marked.parse(fileContent, { async: false }) as string) : '';
+
+	let showRaw = false;
+	// Reset to preview mode when switching files
+	$: if (selectedFile) showRaw = false;
+
 	let pzInstance: PanZoom | null = null;
 
 	const initImagePanzoom = (node: HTMLElement) => {
@@ -59,6 +69,28 @@
 				</button>
 			</Tooltip>
 		{/if}
+		{#if isMarkdown && fileContent !== null}
+			<Tooltip content={showRaw ? $i18n.t('Preview') : $i18n.t('Source')}>
+				<button
+					class="p-1.5 rounded-lg bg-white/80 dark:bg-gray-850/80 backdrop-blur-sm shadow-sm hover:bg-gray-100 dark:hover:bg-gray-800 transition text-gray-500 dark:text-gray-400"
+					on:click={() => (showRaw = !showRaw)}
+					aria-label={showRaw ? $i18n.t('Preview') : $i18n.t('Source')}
+				>
+					{#if showRaw}
+						<!-- Eye icon: switch to preview -->
+						<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5" class="size-4">
+							<path stroke-linecap="round" stroke-linejoin="round" d="M2.036 12.322a1.012 1.012 0 0 1 0-.639C3.423 7.51 7.36 4.5 12 4.5c4.638 0 8.573 3.007 9.963 7.178.07.207.07.431 0 .639C20.577 16.49 16.64 19.5 12 19.5c-4.638 0-8.573-3.007-9.963-7.178Z" />
+							<path stroke-linecap="round" stroke-linejoin="round" d="M15 12a3 3 0 1 1-6 0 3 3 0 0 1 6 0Z" />
+						</svg>
+					{:else}
+						<!-- Code icon: switch to raw -->
+						<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5" class="size-4">
+							<path stroke-linecap="round" stroke-linejoin="round" d="M17.25 6.75 22.5 12l-5.25 5.25m-10.5 0L1.5 12l5.25-5.25m7.5-3-4.5 16.5" />
+						</svg>
+					{/if}
+				</button>
+			</Tooltip>
+		{/if}
 		<button
 			class="p-1.5 rounded-lg bg-white/80 dark:bg-gray-850/80 backdrop-blur-sm shadow-sm hover:bg-gray-100 dark:hover:bg-gray-800 transition text-gray-500 dark:text-gray-400"
 			on:click={onDownload}
@@ -96,8 +128,14 @@
 	{:else if filePdfData !== null}
 		<PDFViewer data={filePdfData} className="w-full h-full" />
 	{:else if fileContent !== null}
-		<pre
-			class="text-xs font-mono text-gray-800 dark:text-gray-200 whitespace-pre-wrap break-all leading-relaxed p-3">{fileContent}</pre>
+		{#if isMarkdown && !showRaw}
+			<div class="prose dark:prose-invert max-w-full text-sm p-3">
+				{@html renderedHtml}
+			</div>
+		{:else}
+			<pre
+				class="text-xs font-mono text-gray-800 dark:text-gray-200 whitespace-pre-wrap break-all leading-relaxed p-3">{fileContent}</pre>
+		{/if}
 	{:else}
 		<div class="text-sm text-gray-400 text-center pt-8">
 			{$i18n.t('Could not read file.')}