What is the iOS Signing Window

The iOS signing window is one of the more obscure details related to the iOS & jailbreak community. The signing window is the window of time in which a certain iOS firmware is able to be updated or downgraded to via iTunes.

Once that signing window closes, it becomes impossible to downgrade or update to that specific iOS version.

A few months back, we compiled the data and put it into a spreadsheet. It got the job done but it was a little hard to read and digest. So, we’ve now created a visual representation of the data.

Below is a bar chart showing how long Apple’s signing period has remained open for every firmware version since iOS 9.

Example

Here’s an example of how to better understand the data presented in the chart below:

iOS 10.2 was released on 12-12-16.

It won’t stop being signed until after the next iOS version is released.

That next version is iOS 10.2.1 and it was released on 1-23-17.

Apple then stopped signing 10.2 on 1-30-17, meaning that there was a 7 day period in between where 10.2 was still being signed (1/23 – 1/30).

This means that you were able to update or downgrade to iOS 10.2 for 7 days after 10.2.1 dropped.

The first firmware shown in the chart (e.g: 10.2 – 10.2.1 = 10.2), is the version that was signed for the shown amount of time.

That’s how the data below is structured and gives us a good forecast for the future. Remember, this is simply historical data and Apple can change things up at any given time.

iOS Signing Window Chart

Notice there hasn’t been once where Apple waited less than a week (7 days) to close the signing period after a new version got released.

You should also take note of how sporadic and unpredictable Apple is with the signing windows.

If you have any questions about the data presented, feel free to let us know on Twitter.

Last updated: 5-16-17