What is Snap URL Preview Service?

Snap URL Preview Service is a specialized web crawler operated by Snap, the company behind Snapchat. This service functions as a bot that visits web pages to generate link previews when users share URLs within the Snapchat application. It was actively operating by at least 2021, though the exact deployment date isn't specified in official documentation.

Technically classified as a web scraper, the Snap URL Preview Service works by requesting web pages and extracting metadata to create rich previews that display when Snapchat users share links. The service identifies itself in server logs with user agent strings like Snap URL Preview Service; bot; snapchat; https://developers.snap.com/robots or similar variants that explicitly identify it as a bot associated with Snapchat.

The service primarily looks for Open Graph tags and Twitter Card metadata to generate previews, creating a visual representation of linked content for Snapchat users. Snap's crawler is designed to be transparent about its purpose and origin, including a reference URL in its user agent string that points to Snap's developer documentation.

Why is Snap URL Preview Service crawling my site?

The Snap URL Preview Service visits your website when Snapchat users share links to your content within the Snapchat application. When a user shares a URL, Snapchat needs to generate a preview card showing relevant information about the linked page, such as its title, description, and a thumbnail image.

The service typically focuses on extracting metadata from your page headers, particularly Open Graph tags (og:title, og:image, etc.) or Twitter Card tags as a fallback. It doesn't crawl your entire site but rather targets specific pages that have been shared by Snapchat users.

Visit frequency depends entirely on how often Snapchat users share links to your content. Popular pages may see more frequent visits, while less-shared content might rarely encounter this crawler. The service also implements caching, typically storing preview data for about 30 minutes before potentially refreshing it with another request.

This crawling is a standard, authorized web practice similar to how other social media platforms generate link previews.

What is the purpose of Snap URL Preview Service?

The primary purpose of Snap URL Preview Service is to enhance the user experience within Snapchat by providing rich, informative previews when users share links. Instead of displaying plain text URLs, Snapchat shows preview cards with titles, descriptions, and images extracted from the linked content.

This service supports Snapchat's social sharing functionality by making shared links more engaging and informative. The data collected is used exclusively to generate these preview cards within the Snapchat application, helping users understand what content they might find if they tap on a shared link.

For website owners, this service provides value by making your content more visually appealing and engaging when shared on Snapchat. Well-implemented metadata can lead to better-looking previews, potentially increasing click-through rates from Snapchat users. The service doesn't index your content for search purposes but rather improves how it appears when shared.

How do I block Snap URL Preview Service?

The Snap URL Preview Service respects standard robots.txt directives, making it straightforward to control its access to your website. If you wish to block this crawler from accessing specific parts of your site or your entire site, you can add the following directives to your robots.txt file:

User-agent: Snap URL Preview Service
Disallow: /private-directory/

This example would prevent the service from accessing any content within the "/private-directory/" path. To block the service from your entire site, you could use:

User-agent: Snap URL Preview Service
Disallow: /

However, blocking the service completely means that when users share links to your content on Snapchat, they won't generate rich previews. Instead, links may appear as plain text or with minimal information, potentially reducing engagement with your content on the platform.

If you only want to prevent specific pages from generating previews, you can implement more targeted disallow rules. The service is designed to be respectful of website owners' preferences and will adhere to properly formatted robots.txt directives.

Before implementing blocks, consider that allowing the service to generate previews for your public content can enhance how your site appears when shared on Snapchat, potentially driving more traffic to your website from the platform's users.

Snap URL Preview Service