Understanding Timeouts


The use of timed events can present significant barriers for users with cognitive disabilities, as these users may require more time to read content or to perform functions, such as completing an online form.

During the completion of an online process for reserving a hotel room and purchasing a plane ticket, a user with a cognitive impairment may become overwhelmed with the amount of instruction and data input required to complete the process. The user may not be able to complete the process in one sitting, and may need to take a break. Ideally, users should be able to leave a process without losing their current place within the process, and without losing data that have already been entered. If users cannot take a break and check their work, many will often be unable to complete a task correctly.

For situations where the absence of a timed event would significantly change the intended functionality of an application (e.g., an auction or another real-time event), it is important to ensure that users with disabilities are properly notified. Notifications should include information about timed events, and an indication of the duration of the time given. As well, they should include mechanisms clearly labeled to adjust, extend, or stop the duration of an event, to allow users to fully engage and interact with Web content and functionality. For example, if an e-commerce Web site's checkout process provides secure credit card transactions, the user is notified of the timeout, and is given time to extend it.

When there is a chance to extend a time limit, it should be noted that many users, within 20 seconds, cannot read instructions to extend a time limit.  Using simple text can reduce the time it takes to read these instructions.

This success criterion only applies to timeouts that are within the content providers knowledge or control. For example, if the user closes a web browser or device, and looses content in an open page that has not yet been submitted, the success criteria has not been violated.


This Success Criterion helps users who need additional time performing tasks or reading content.

A user can take a break and check their work without needing to start again. This enables many users to complete tasks online that they otherwise could not do.

If a situation exists where a timeout is necessary, the user is warned at the start of the task about the length of inactivity that would generate a timeout. The user  can then decide if they can manage this task or not in the given time. This will  reduce the frustration of working hard at a task just to have all their work deleted due to a timeout.

This Success Criterion helps people with many different cognitive disabilities, including people with:





Techniques that are sufficient to meet the Guideline or Success Criterion.