Animation Requirements for the Web

Animations include dynamic elements such as interactive images and games. For developing animations, follow NREL's design and coding requirements.

Use the multimedia quality assurance checklists to ensure your animation meets all of NREL's requirements.

Section 508 Requirements

Following are the guidelines for creating Section 508-compliant animations.


Select colors that provide sufficient contrast. Color should not be used as the only way to convey the message. Animations should not override user-selected contrast and color selections and other individual display attributes.


Provide a well-defined, on-screen indication of the current focus that moves among interactive interface elements as the input focus changes. The focus should be programmatically exposed so that assistive technology can track focus and focus changes.

Keyboard Support

People who have difficulty controlling a mouse may find it more efficient to use a keyboard. Screen readers also use the keyboard to navigate through the page. Therefore, all interaction controls should be accessible from the keyboard.


Provide download links to any plug-ins or applications that are required to interpret the content.

Screen Flickering

An animation must not flicker with a frequency of greater than 2 Hz and lower than 55 Hz.


The webpage containing the animation should still be usable when the script is turned off.

Text Versions

Animations must have a text version to be compliant with Section 508's accessibility requirements. The text version should include a full transcript of all of the speech, text, and action that happens in the animation.

Timed Responses

When a timed response is required, the user should be alerted and given sufficient time to indicate more time is needed.

For guidelines on making animations natively more accessible, see or the National Center for Accessible Media.

Technical Requirements

Animations should work on all every browser in NREL's browser testing suite.