Review pop-ups, modals, and banners that obscure page content. Identify mobile usability and search visibility concerns, then improve dismissal controls and keyboard focus, the element currently receiving keyboard input.
Use when applies to CSS and JavaScript implementations of modals, overlays, pop-ups, cookie banners, newsletter sign-up dialogs, and promotional overlays. Check for `position: fixed`, `position: absolute` with large z-index, backdrop overlays, and JavaScript that shows modals on page load or shortly after. Consider both SEO impact (Google) and accessibility (WCAG focus management).
Review the instructions the agent will receive before you install.
Intrusive interstitials are a barrier for screen reader users who may not know a modal is blocking the page — they hear content that appears interactive but cannot activate it. Keyboard users may find focus trapped behind an overlay with no way to dismiss it. Users on mobile are most affected visually, as full-screen pop-ups eliminate all access to content until dismissed. Additionally, Google Search penalizes mobile pages with intrusive interstitials in search rankings.
Identify elements using position: fixed or position: absolute with high z-index values that cover significant portions of the viewport. For each: (1) Does it appear on page load or within a few seconds? (2) Does it cover more than a small portion of the main content on mobile screens (< 600px width)? (3) Is it easily dismissible — is there a visible close button with an accessible name? (4) Can it be dismissed by pressing the Escape key? (5) Does focus move into the dialog when it opens and return to the trigger when it closes? Flag dialogs that fail any of these checks.
(1) Replace full-screen page-load pop-ups with: (a) sticky banners at the top or bottom (max-height 10-15% of viewport), (b) inline content blocks within the page, or (c) slide-in panels that do not cover the main content. (2) For legally required notices, use small sticky banners rather than full-screen overlays. (3) For all modal dialogs that must be used: implement ARIA dialog pattern — add role='dialog', aria-modal='true', aria-labelledby pointing to the dialog title; trap focus within the dialog using a focus trap; move focus to the first focusable element inside the dialog on open; close on Escape key; return focus to the trigger element on close. (4) Delay non-critical pop-ups until user interaction rather than triggering on page load.
Intrusive interstitials create two categories of problems: (1) SEO: Google's Intrusive Interstitials Update (2017) penalizes pages that show pop-ups covering the main content on mobile immediately after navigating from search results. Exempt are legally required notices, age verification, and login walls for gated content. (2) Accessibility: A modal dialog that does not manage focus is a WCAG failure. If a screen reader user cannot tell a dialog has appeared, or cannot navigate to it, or is trapped in it without being able to escape, the page fails WCAG 2.1 SC 2.1.2 (No Keyboard Trap) and SC 4.1.3 (Status Messages). The WAI-ARIA dialog pattern requires focus management as a baseline requirement.
Review stylesheets, component styles, and responsive states related to Avoid intrusive interstitials. Flag exact selectors, declarations, or breakpoints that violate the rule in the rendered UI.
For full implementation details, code examples, and framework-specific guidance,
see references/rule.md.
Rule page: https://frontendchecklist.io/rules/css/interstitials
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.