How to block Snap URL Preview Service
Operated by Snap. is a bot operated by Snap that fetches web page content to generate URL previews and rich link cards for links shared in Snapchat conversations. … Fetcher Retrieves web page metadata to power app features like link previews or feeds
How it identifies itself
Mozilla/5.0 (iPhone; CPU iPhone OS 16_2_2 like Mac OS X) AppleWebKit/526.3.23 (KHTML, like Gecko) Version/16.2 Mobile/15E148 Snapchat/11.13.0.31 (like Safari/526.3, panda)
robots.txt
What the agent asks to be told. It obeys this or it does not — nothing enforces it.
User-agent: Snap Disallow: /
nginx
In the server block, then reload.
# In the server block. 403 rather than 444: a closed connection tells the
# operator nothing, and an agent that gets a status code can log it.
if ($http_user_agent ~* "(Snap|Snap URL Preview Service; bot; snapchat; https:|Snap URL Preview Service)") {
return 403;
}
Apache
In .htaccess or the vhost.
BrowserMatchNoCase "Snap" bad_bot
BrowserMatchNoCase "Snap URL Preview Service; bot; snapchat; https:" bad_bot
BrowserMatchNoCase "Snap URL Preview Service" bad_bot
<RequireAll>
Require all granted
Require not env bad_bot
</RequireAll>
Cloudflare
Security → WAF → Custom rules.
# Security → WAF → Custom rules, action: Block (http.user_agent contains "Snap") or (http.user_agent contains "Snap URL Preview Service; bot; snapchat; https:") or (http.user_agent contains "Snap URL Preview Service")
WordPress
A child theme's functions.php, or a small plugin.
// functions.php of a child theme, or a small plugin. Runs before WordPress
// builds the page, so a blocked agent costs one PHP process and no queries.
add_action('init', function () {
$agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
foreach (['Snap', 'Snap URL Preview Service; bot; snapchat; https:', 'Snap URL Preview Service'] as $needle) {
if (stripos($agent, $needle) !== false) {
status_header(403);
exit('Blocked: Snap URL Preview Service');
}
}
});
robots.txt is a request. The rules below it are the wall.
Snap URL Preview Service publishes a token, so the directive above will work for as long as it keeps honouring it — and nothing except its own good manners makes it. The server rules match on a header the requester sets, which stops the agent that says who it is and not the one that copies somebody else's name. Botscope verifies identity against DNS and published address ranges, records which check decided each request, and shows you the ones that lied.