Review GIFs, videos, and CSS animations for rapid flashing that may trigger seizures in photosensitive users. Check flash frequency and screen area, then suggest removing or slowing effects or replacing them with fades or static content.
Use when reviewing rendered HTML, interactive components, or design-system patterns related to Prevent seizure-triggering flashing content. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.
flashing-content reviews GIFs, videos, and CSS animations for rapid flashing and helps revise effects with photosensitive users in mind. It checks both flash frequency and the proportion of the screen occupied by flashing content. Possible changes include removing the effect, slowing it down, or replacing it with a fade or static presentation. It identifies the specific elements involved and suggests ways to convey the same information without flashing.
Use it before publishing animated images or videos, or when reviewing visual effects on a web page. It also helps examine existing CSS animations for rapid flashing and consider alternative presentations.
The source identifies flashing more than three times per second, flashing that covers at least 25% of the viewport, and red flashing as patterns to check for and avoid. Flash frequency is measured with animation tools. Because flashing may trigger seizures in people with photosensitive epilepsy, treat this as a safety check related to WCAG 2.3.1.
This overview was written by AI (OpenAI Codex) from the public SKILL.md. Check the original below for the exact behavior.
AI rated this skill on four points using only the contents of its SKILL.md. Stars and popularity are not taken into account.
The total counts each point as A = 25, B = 15, C = 5. Rated by AI (OpenAI Codex) as of Oct 23, 2026. Treat it as a guide and read the original before installing.
Review the instructions the agent will receive before you install.
Flashing content between 3-60 Hz can trigger seizures in people with photosensitive epilepsy—this is a critical safety requirement, not just an accessibility preference.
Verify no content flashes more than 3 times per second, and that any flashing content occupies less than 25% of the viewport. Test animated GIFs, videos, and CSS animations for rapid flashing patterns.
Remove or slow down rapid flashing animations. Use animation tools to measure flash frequency. Replace flashing effects with fade transitions or static alternatives that convey the same information.
Explain how flashing content between 3-60 Hz can trigger seizures in people with photosensitive epilepsy, and why this is a critical accessibility and safety requirement under WCAG 2.3.1.
Review the rendered markup and interactive states that affect Prevent seizure-triggering flashing content. Flag exact elements, roles, labels, focus behavior, or keyboard interactions that violate the rule, and note how to verify the fix with browser accessibility tooling or assistive tech.
For full implementation details, code examples, and framework-specific guidance,
see references/rule.md.
Rule page: https://frontendchecklist.io/rules/accessibility/flashing-content
No reviews yet. Tell others what you thought.
No login needed. Share how it worked for you, ask a question, or note where it did not run.
No comments yet. Be the first to write one.
Create and review custom 404 pages that help visitors recover from broken or moved links through search and navigation. Check the rendered page and HTTP response so missing content returns a proper 404 status.
Audit or create a dedicated About page that explains a website’s purpose and identifies its people or organization. Review the rendered output and supporting information, including expertise and contact details, to find gaps.
Review and add automated accessibility checks for components, pages, and continuous integration workflows. Use axe-based tools to detect structural and attribute issues, while identifying checks that still need keyboard or screen reader testing.
Review sign-in, registration, multi-factor authentication, and account recovery for accessibility barriers. Find blocked paste, difficult code entry, and inaccessible backup methods, then suggest authentication paths that support password managers, autofill, or device approval.
Review form errors, success messages, and live updates so screen reader users receive important notifications. Check the HTML delivered to the browser, announcement settings, display duration, and dismissal controls, then identify specific elements that need changes.
Review HTML tables so screen reader users can understand how headers and data relate. Check header markup, table descriptions, and merged cells, then identify specific fixes and ways to verify them.