12 · Language, Readability and Flashing elements

Web 2.0 Services

Items that flash or blink at a certain rate can cause seizures and should be avoided. They can also be very distracting and make other elements on a page hard to read. Complex text can make text harder to read for some people with cognitive learning disabilities and specific learning differences including dyslexia. The language used needs to be understandable for all users and where other languages are introduced on a page there needs to be markup language added to elements and attributes that can accessed by assistive technology such as screen readers to ensure the correct pronunciation - this means it can be 'programmatically determined'.

Outcomes and Scores

This test has 4 possible outcomes.

Outcome Score
All languages have been approprately coded and text readable. No flashes affecting viewing. 100%
Reading levels are satisfactory but language changes have not always been programmatically determined on minor pages. No flashing elements. 67%
Some flashing content. Where language changes occur there is no way that assistive technologies can recognise the change so pronunciation is incorrect. 33%
Any blinking or flashing content that flashes more than three times in one second. Language has not been stated for the page or sections. 0%


The results of this test are taken into account when calculating accessibility scores for the following disabilities.


The following technique may come in handy when running this test.


This test aims to cover the following sections of best practice.

Document Section Heading
WCAG 2.1 2.3.2 Three Flashes More Info
WCAG 2.1 3.1.1 Language of Page More Info
WCAG 2.1 3.1.2 Language of Parts More Info
WCAG 2.1 3.1.4 Abbreviations More Info