Even if you “View Source” on a post page, you’ll see similar emptiness—the actual post text is loaded via XHR/Fetch after page load.
Any website or tool claiming to "View Facebook private message source code" is either malware, a phishing scam, or a cookie stealer. Do not enter your password into any third-party "source viewer." view sourcehttpsweb facebook
While you can edit the code in the "Inspect" tool to change how Facebook looks on your screen (like changing a friend's name as a prank), these changes are local. They disappear the moment you refresh the page and do not affect Facebook’s servers. A Word on Security Even if you “View Source” on a post
Then, open DevTools and compare the view-source: output to the tab. The Elements tab shows the current DOM after all scripts have run. That is the real "source" of what you see, but it is generated dynamically, not sent over HTTPS as static code. They disappear the moment you refresh the page
If you want to know what Facebook allows robots to see, visit https://facebook.com/robots.txt . This is not source code, but it reveals Facebook’s boundaries for crawling. Disallowed paths like /ajax/ and /pages/messages/ hint at sensitive areas.