Identify what the address returns
A share button commonly produces a viewing page. That page can load a player, require a cookie or redirect through a login screen. The video file is a separate resource. For non-YouTube hosting, locate the provider’s supported direct-video address and check what a signed-out browser receives.
A filename ending in .mp4 is a useful clue, but it is not proof. A server can return an error page at that address. Equally, an extensionless URL can return video correctly. That is why this checker separates text validation from network verification.
Check stability and access separately
Look for expiration timestamps or signatures in the query string. They may be legitimate for private delivery but unsuitable for a stable public asset. Ask the hosting configuration for a persistent URL rather than repeatedly replacing an expired one. Also review access controls, redirects and crawler rules at the host.
- Open a fresh signed-out session.
- Confirm the final destination after redirects.
- Check that the same address is not reused for an unrelated product video.
Preserve URL encoding when building the feed
Special characters must remain unambiguous. The snippet builder encodes commas inside a URL so they cannot be mistaken for separators between repeated values. Do not decode those commas again in a spreadsheet or export script. Review the final text after the last data transformation, because an intermediate tool can change a previously correct value.