The movie "Insidious" is available to watch on several streaming platforms depending on the region:

• In the United States, "Insidious" is currently streaming on HBO Max, HBO Max Amazon Channel, and Hulu.
• You can also rent or buy it on Amazon Video, Apple TV, and Fandango At Home.
• In the United Kingdom, it is streaming on Sky Go and Now TV Cinema, with options to rent or buy on Amazon Video, Rakuten TV, and Sky Store.
• It is also available to stream on Netflix and Hulu in some cases for specific films in the franchise.

There are no free streaming options currently available for "Insidious." Renting or purchasing digitally might be the best option if not subscribed to these platforms.