This reference explains every check in FooGallery Media Audit ruleset r4.0. Each rule has a stable heading anchor, so FooGallery and support articles can link directly to the matching explanation.
A single image can contribute to more than one finding. Counts and coverage describe the saved audit run and do not update until you run the audit again.
Finding severity
- Error: a broken or missing resource that usually needs attention.
- Warning: an observed request or resource that may fail and should be investigated.
- Info: an optimization, accessibility, or gallery-configuration suggestion to review.
Quick links to all checks
- FG-DEL-02: Thumbnail upscaled from a smaller image
- FG-DEL-04: Rendered modern-format delivery has not been verified
- FG-SRC-01: Large source image (storage observation)
- FG-SRC-05: Image file missing from the server
- FG-INT-01: Gallery points at images that cannot be found
- FG-INT-02: Image is in the library but will not load
- FG-A11Y-01: Images with no alt text
- FG-A11Y-02: Alt text is a camera or screenshot filename
- FG-A11Y-03: Placeholder alt text
- FG-A11Y-04: Same alt text repeated across images
- FG-A11Y-05: Very long alt text
- FG-CFG-01: Review lazy loading configuration
- FG-CFG-02: Very long gallery with no paging
Delivery and source checks
FG-DEL-02: Thumbnail upscaled from a smaller image
Severity: Info
What it means: A gallery requests a fixed thumbnail width or height that is larger than the original image recorded in WordPress. Enlarging a smaller image can make the thumbnail look soft or pixelated.
When it appears: This check runs only for gallery layouts that use fixed thumbnail dimensions. Layouts without a fixed thumbnail-size concept are marked not applicable. If WordPress has no width or height metadata for the image, the check is incomplete rather than guessing.
What to do: Upload a larger version of the image, or reduce the gallery’s thumbnail dimensions so FooGallery does not need to stretch it. After changing the image or gallery settings, run the audit again.
FG-DEL-04: Rendered modern-format delivery has not been verified
Outcome in ruleset r4.0: Unavailable; this rule does not produce an actionable finding.
What it means: A server-side request to an original image cannot prove which format a visitor’s browser receives after FooGallery, an optimization plugin, a host, a CDN, and browser content negotiation have all done their work. FooGallery therefore reports this check as unavailable instead of making a site-wide WebP or AVIF claim from an unreliable sample.
What to do: No repair is required because this is a measurement limitation, not evidence of a problem. If you want modern image formats, review your image-optimization plugin, hosting controls, or CDN settings and verify a rendered gallery in a browser.
FG-SRC-01: Large source image (storage observation)
Severity: Info
What it means: The original Media Library image is wider or taller than 2,500 pixels, larger than 1 MiB, or both. The audit reads the local file size when available and can fall back to the file size in WordPress attachment metadata.
Important: This is a source-storage observation. It does not prove that visitors download the full original, and it does not estimate page weight. FooGallery can serve generated thumbnails that are much smaller.
What to do: If the original exists only for web viewing, keep a backup and consider resizing or compressing it with a trusted bulk image-optimization tool. Keep the original when visitors need to download it, you need it for print, or your workflow depends on the full resolution.
FG-SRC-05: Image file missing from the server
Severity: Error
What it means: WordPress has an image attachment record, but the file is not present at its local path and the attachment URL returned a confirmed HTTP 404 or 410 response.
What it does not mean: A timeout, blocked request, redirect, invalid URL, or exhausted network budget is recorded as unavailable coverage and does not create this missing-file error. A healthy offloaded image that returns a successful response is not marked missing.
What to do: Restore or re-upload the missing file, correct the attachment if WordPress points at the wrong location, or remove or replace the image where it is used. Missing files often follow an incomplete migration, restore, or media offload change.
Gallery integrity checks
FG-INT-01: Gallery points at images that cannot be found
Severity: Error
What it means: A saved gallery member does not resolve to a current, non-trashed WordPress image attachment. The saved value may be missing, deleted, zero, or point to a different post type. This can leave a blank slot in the gallery.
What to do: Edit the affected gallery and remove or replace the missing item. For a dynamic gallery, also check the gallery’s data source and its filters. An unsupported dynamic source is reported as unavailable coverage instead of being treated as an empty gallery.
FG-INT-02: Image is in the library but will not load
Severity: Warning
What it means: The image attachment exists, but a bounded HTTP request to a sampled image URL returned an error status of 400 or higher. The audit samples the first valid image URL it encounters in each gallery; it does not request every gallery image.
What to do: Use View affected images and open the sampled URL. A 403 commonly points to permissions, authentication, or hotlink protection. A 404 means the file is not where the URL says it is. A 5xx response points to a server or upstream service problem. Check caching, CDN, security, and media-offload settings as appropriate, then retest the public gallery.
Coverage note: Redirects, transport failures, and exhausted request budgets remain unknown. A passed sample is not proof that every image URL works.
Accessibility checks
These rules use the alt text rendered by a supported gallery data source when available; otherwise they use the attachment’s alt text. They are review prompts, not automatic accessibility verdicts. Decorative images may correctly use empty alt text.
FG-A11Y-01: Images with no alt text
Severity: Info
What it means: The alt-text value is empty after surrounding spaces are removed.
What to do: If the image communicates information, add concise alt text in the Media Library that describes its purpose or what it shows. If it is purely decorative and should be ignored by assistive technology, empty alt text can be correct.
FG-A11Y-02: Alt text is a camera or screenshot filename
Severity: Info
What it means: Alt text starts with a common camera or screenshot filename pattern: IMG, DSC, DSCN, or Screenshot, followed by optional spacing, an underscore or hyphen, and digits.
What to do: Replace the filename with a useful description of the image. Describe the purpose or relevant visual information rather than repeating technical file details.
FG-A11Y-03: Placeholder alt text
Severity: Info
What it means: Alt text exactly matches image, photo, picture, placeholder, or test, ignoring capitalization.
What to do: Replace the placeholder with text that communicates what matters about this specific image. If the image is decorative, use intentional empty alt text instead of a placeholder.
FG-A11Y-04: Same alt text repeated across images
Severity: Info
What it means: Three or more images in the same gallery use identical non-empty alt text, ignoring capitalization. The first two do not trigger the rule; when the third is found, all three are included, and later matches are added individually.
What to do: Review the affected images. Give each informative image alt text that distinguishes its relevant content. Repetition can be intentional in a few cases, so use context rather than changing text only to silence the audit.
FG-A11Y-05: Very long alt text
Severity: Info
What it means: The current rule flags trimmed alt text longer than 125 bytes. This is a review heuristic, not a standards-based legal or technical maximum. Text containing non-ASCII characters can reach the byte threshold in fewer than 126 visible characters.
What to do: Keep the alt text focused on the image’s purpose, usually around one sentence. Put supporting detail in the visible caption or nearby body copy. Do not remove information that a visitor needs simply to meet a number.
Gallery configuration checks
FG-CFG-01: Review lazy loading configuration
Severity: Info
What it means: A gallery has more than 20 members, its layout supports FooGallery lazy loading, and lazy loading is disabled either for that gallery or site-wide.
What to do: Edit the gallery and review its lazy-loading option under Gallery Settings > Advanced. Also check the global FooGallery setting if lazy loading is disabled across the site. Enable it when loading images as visitors scroll is appropriate, then test the public gallery with your cache and optimization setup.
When it does not apply: Layouts that do not declare lazy-loading support are marked not applicable instead of receiving this suggestion.
FG-CFG-02: Very long gallery with no paging
Severity: Info
What it means: A gallery has more than 100 members, its layout supports paging, and no paging mode is saved. Existing paging, dots, load-more, or other supported paging configuration prevents this finding.
What to do: Edit the gallery and enable an appropriate paging or load-more mode so visitors can reach the first screen of images sooner. Review FooGallery Paging Settings for the available controls in your plan and layout.
When it does not apply: Layouts that do not declare paging support are marked not applicable.
Next steps
Return to Using FooGallery Media Audit for instructions on running an audit, reading coverage, opening affected-image details, and managing the saved report.
