How long is an open work permit valid?

There is no single fixed length for an open work permit. The duration depends on which category you qualify under and is stated on the permit document itself.

In many cases the validity is tied to a related factor, for example the length of your spouse's work or study permit, your eligibility window for a PGWP, or the time needed to process another application such as permanent residence. Your permit cannot be valid longer than your passport, so make sure your travel document covers the period you are requesting.