Expiring Signed URLs: Why Some Download Links Die After Minutes
If you have ever pasted a video link into a downloader, got a perfectly good download link, and then come back ten minutes later to find it dead, you have met an expiring signed URL. It is not a bug. It is the CDN doing exactly what it was told to do, and once I understood how it works, it changed how I built my downloader. What a signed URL actually is A signed URL is a normal file URL with a…
Signed URLs are a common method for video platforms to prevent files from being hotlinked forever. When a user downloads a file, the platform provides a signed URL that is valid for a few minutes. This time limit ensures the link is useless once it leaks onto a forum. The issue arises when a tool like a downloader shares the same link with a person, expecting them to click it promptly.
If the user delays clicking the link by minutes, the CDN will reject the request, thinking the link is invalid. This leads to confusion for both the user and the developer, as the link appears broken when it's simply expired. To avoid this, developers should fetch the download URL only when the user selects the desired quality, reducing the gap between link creation and usage.
Keeping the flow short by displaying file sizes next to quality options helps users make a quick decision. Avoid caching resolved links, as they quickly become useless. Lastly, if a download fails due to an expired link, inform the user clearly and provide the option to generate a fresh link. By following these practices, developers can ensure a better user experience when dealing with expiring signed URLs.
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