Work through this before launch; every item is something that regularly ships broken.

Brand Assets

  • Favicon present, in ICO and SVG, plus a 180 px apple-touch-icon. Check it appears in a browser tab, a bookmark, and on a phone home screen.
  • App icons and manifest icons (192 px and 512 px) if the site is installable.
  • Logo variants: light and dark backgrounds, horizontal and stacked, with adequate clear space.
  • Logo is vector (SVG) wherever possible.

Social Sharing

  • Open Graph image at 1200 × 630, absolute URL, under 8 MB.
  • Twitter card tags with an image.
  • Per-page images where they add value — articles and products should not all share the site-wide default.
  • Test the actual render in each platform's preview/debug tool. Social scrapers cache aggressively, so verify before announcing, not after.
  • Confirm the OG image isn't accidentally overridden by a page-level metadata object — a very common bug.

Performance

  • Hero image is not lazy-loaded and is prioritized.
  • No image served far larger than its display size. Inspect the largest images and compare intrinsic to rendered dimensions.
  • Modern formats (WebP/AVIF) with fallbacks.
  • Width and height declared on every image so nothing shifts during load.
  • Total image weight on key pages within budget — aim under ~1 MB for a landing page.
  • Responsive sizes actually working: check what a phone downloads, not just what the desktop gets.

Content and Accessibility

  • Alt text on every meaningful image, empty alt on decorative ones.
  • No critical information available only inside an image — prices, deadlines, contact details.
  • Contrast checked for any text over images, including at mobile crops.
  • Dark mode checked: transparent PNGs with dark artwork, white-background logos, images with baked-in white borders.
  • Descriptive filenames, not IMG_1234.jpg.

Legal and Housekeeping

  • Licences documented for every third-party image, with IDs and dates stored somewhere durable.
  • Editorial-only images not used commercially.
  • Model and property releases on file for identifiable people in marketing imagery.
  • Placeholder and lorem images removed — the classic launch embarrassment is a stock photo of the wrong industry, or a "Coming soon" placeholder in the footer.
  • Test and demo data removed from screenshots.
  • Personal or internal information redacted in any screenshot.

After Launch

Some things can only be checked live:

  • Share a URL in a chat app and a social platform and look at the preview that appears.
  • Load the site on a real phone on mobile data, not wifi.
  • Run Lighthouse on the live site, not just locally.
  • Check the site in dark mode on a real device.
  • Look at the search results a week later to confirm the favicon and any image indexing appear as intended.

Keep the List

Save this as a template and re-run it at every major release. Image regressions are quiet — nothing errors, nothing fails a test, the page simply looks slightly worse or loads slightly slower until someone notices months later.