A temporary link is a permission with an end time. It may be signed, tied to a session, limited to one purpose or valid only for a short window. Copying the URL does not extend that permission.
FAST-VID's download and preview links are temporary and purpose-specific. The current defaults are 300 seconds for a download token and 1,200 seconds for a preview token, both configurable. Tokens are bound to the relevant job and session.
What a signed or temporary URL is
A signed URL includes a signature or token that authorizes a request under conditions set by the server. Common conditions include an expiry timestamp, a permitted method, a resource path, a session or a maximum number of uses.
The server verifies the signature before returning the resource. If the signature is invalid, the link was modified or the expiry has passed, the server can respond with an error instead of the file.
A temporary URL is not necessarily a secret in the cryptographic sense, but it can grant access while valid. Treat it like a key to the resource and avoid posting it publicly.
Why services use access windows
Short windows limit exposure if a link is copied into a chat, log, screenshot or browser history. They also let a service rotate access without changing the underlying file or storage location.
Expiry can enforce a workflow: a preview link is valid long enough to watch, and a download link is valid long enough to save the file. A shorter window reduces the chance that an old link remains useful after the user has moved on.
Expiration is not a complete security system. A link can still be used by anyone who obtains it during its valid window, so access should also be scoped and the service should use HTTPS and appropriate authorization.
Expiry, session binding and purpose
A link can expire for several reasons: the timestamp passed, the session ended, the job was deleted, the token was already used, or the token was issued for a different purpose. Those are different failures even if the browser shows a similar error.
A download token may be bound to a job and session. A preview token may be separately scoped and shorter or longer. A token for one file should not authorize another. This reduces the impact of a leaked link.
Some services bind links to an IP address or device; others do not. Do not assume that a link is tied to your location unless the service documents it. A valid link can work from another network if the server does not enforce that binding.
| Failure | Possible meaning | Safe response |
|---|---|---|
| Expired | The access window ended | Request a fresh link from the service |
| Invalid signature | The URL was modified or corrupted | Use the original link or request a new one |
| Wrong session | The link is bound to another browser session | Return to the original session and request again |
| File missing | The job or media was deleted or retained past its window | Check the service’s retention message |
| Wrong purpose | A preview token was used for download or vice versa | Request the correct link type |
Expired link versus deleted file
An expired link means the authorization is no longer valid. A deleted file means the resource itself is gone. A server may return the same status for both to avoid revealing whether a private file exists, so the message alone may not distinguish them.
If a fresh link from the same service works, the old link was probably expired or scoped incorrectly. If a fresh link also fails, the job may have expired, the file may have been removed, or the source may no longer be available.
Do not try to extend a timestamp, edit a signature or reuse a token outside its purpose. Those actions do not create valid authorization and may violate access controls.
FAST-VID download and preview links
FAST-VID issues short-lived tokens for completed files. The current defaults are 300 seconds for download and 1,200 seconds for preview. Both are deployment-configurable, so the observed lifetime can differ.
Tokens are bound to the relevant job and session and are separated by purpose, so a preview token is not a download token and a token for one job is not valid for another. The link is intended for the current browser workflow, not for permanent public sharing.
This article does not reveal token values, signing material, private endpoints or internal infrastructure. FAST-VID does not provide a way to extend a token or bypass its expiry. If a link expires, return to the downloader and start or request the file again.
Safe troubleshooting
First confirm that the file is still within the service’s retention window. Then return to the original page or service and request a fresh download or preview action. Do not copy an old URL from history and assume it will work.
If a fresh link fails immediately, check whether the job completed, whether the browser session is still the same and whether the file type is supported. If the source itself is gone, a new token cannot restore it.
For a public-link downloader, the right recovery path is another supported public link and a new job. For a private or protected service, use its official playback or download feature.
A practical access-window example
Suppose a completed file link is valid for five minutes. If you copy it into a message and open it an hour later, the server can reject it even though the file is still stored. Requesting a fresh link from the original page is the correct recovery.
If the fresh link also fails immediately, the job may have expired or the file may have been removed. The distinction matters because extending the old URL cannot fix a deleted resource.
Frequently asked questions
Why did my media link stop working?
The access window may have expired, the session may have changed, the job may have been deleted or the link may have been issued for another purpose.
Does an expired link mean the file was deleted?
Not necessarily. The authorization may have expired while the file still exists. A fresh link is the safe way to test.
Can I edit the expiry time in the URL?
No. Modifying a signed URL invalidates it and does not create authorization. Request a fresh link instead.
How long do FAST-VID links last?
The current defaults are 300 seconds for download tokens and 1,200 seconds for preview tokens. Both are configurable and may differ in a deployment.
Are FAST-VID tokens tied to my IP address?
Tokens are bound to the relevant job and session in the inspected code. This article does not claim an IP-address binding.
Sources and references
Try FAST-VID
Open the FAST-VID downloader for a supported public link. If a download link expires, return to the page and request a fresh one; tokens cannot be extended manually.