AI 404ページジェネレーター。

Create a not-found page layout, vertically centered in the viewport: a large 404 numeral as a display element, an h1 stating that the page was not found in plain language, one sentence explaining it may have moved or been deleted, and a primary Back to home button. Reuse the site header and footer so the page does not read as a different site. The route must return an HTTP 404 status, not a 200 with error copy on it, or search engines will index the dead URL. Give the h1 focus on load so screen reader users land on the error rather than the nav, and keep the numeral decorative with aria-hidden so it is not announced as a number.

Create a not-found page built around a search affordance: a compact 404 heading, one line of copy, then a labelled search input with an autofocus and a submit button that posts to the site search route. Below it, list five popular or recently updated pages as real links rather than a generic Back to home. Seed the search input with any meaningful slug segment from the failed URL so the visitor starts from their own query. Return an HTTP 404 status from the route and do not redirect to the homepage. Label the input with a visible label, announce result counts through an aria-live region, and keep the header and footer navigation intact.

Create a not-found page for a developer tool: a monospace 404 with a faint glow on a dark surface, a short headline, one line noting the page may have moved between versions, and a docs search input. Add links to the docs index, the changelog and the version switcher, since a broken docs URL is usually a version mismatch rather than a typo. Return an HTTP 404 status and keep the docs sidebar rendered so the reader retains their place in the tree. Set the h1 as the focus target on load, mark the background texture aria-hidden, and hold contrast at 4.5:1 for the muted supporting copy against the dark background.

Create a not-found page for a store: a short heading acknowledging the product or page is unavailable, a product search input, a row of four top-level category links, and a grid of four bestseller cards with image, name and price. Explain in one line that items can sell out or be renamed. Return an HTTP 404 status for the missing URL — a soft 404 redirecting to the homepage strands the visitor and keeps the dead link indexed. Give every product image real alt text, keep the cards keyboard reachable in reading order, and preserve the cart indicator in the header so an in-progress basket is visibly intact.

Create an in-app not-found view that renders inside the authenticated shell with the sidebar and top bar intact: a compact heading stating the resource was not found, one line noting it may have been deleted or belongs to a different workspace, a Back to dashboard button, and a link to switch workspace. Do not sign the user out or bounce them to the marketing homepage. Return an HTTP 404 for a genuinely missing resource and a 403 where the resource exists but is not theirs, since conflating the two leaks whether an ID is real. Move focus to the heading on render and keep the page title informative for browser history.

Create a brand-led not-found page: a full-bleed illustration or looping animation filling the viewport, an oversized 404 or short witty headline set over it, one line of copy, and a single high-contrast Back to home button that stays legible against the artwork. Mark the illustration aria-hidden and carry all meaning in the text. Respect prefers-reduced-motion by holding a static frame instead of looping. Keep the total weight in check — a 3MB hero on an error page is bandwidth spent on a failed request. Return an HTTP 404 status and keep the footer navigation present beneath the artwork.