FooGallery Media Audit Findings Reference

This reference explains every active check that is performed in a FooGallery Media Audit.

Audit ruleset : r4.2 (build 0.13.0). Last updated : 17 Sep 2026.

Please note : a single image can contribute to more than one finding.

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.

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-SRC-01: Large source image

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-04: Image source uses JPEG or PNG

Severity: Info

What it means: The image stored in the WordPress Media Library uses JPEG or PNG as its source format. FooGallery normally identifies the format from the attachment’s registered MIME type. If that is unavailable or unrecognized, it can use the attached filename, saved metadata filename, or attachment URL extension as a fallback.

What it does not mean: This does not prove that visitors receive a JPEG or PNG file. FooGallery, an image-optimization plugin, the web host or a CDN may convert or rewrite the rendered image and deliver WebP or AVIF instead.

What to do: If reducing source storage is useful for your workflow, consider converting or replacing the Media Library source with a WebP or AVIF version. Keep the original when it is needed for downloads, printing, editing, archival purposes or another workflow. Test affected galleries after replacing an image.

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.

FG-SRC-07: Image may benefit from compression

Severity: Info

What it means: The image’s source file is unusually large for its pixel dimensions. FooGallery calculates the file’s bytes per pixel and reports a finding only when the file is larger than 256 KiB and exceeds the conservative threshold for its format:

JPEG, WebP and AVIF: more than 0.75 bytes per pixel
PNG: more than 2 bytes per pixel

Both limits must be exceeded. A value exactly equal to a limit does not produce a finding.

What it does not mean: This finding does not prove that the image is poorly compressed or predict how many bytes an optimizer could save. Detailed photographs, transparency and lossless images can legitimately require larger files. It also describes the stored source file, not necessarily the image delivered to visitors; FooGallery, an optimization plugin, the host or a CDN may serve a smaller version.

When it appears: The check applies to static JPEG, PNG, WebP and AVIF files stored locally. Known animated images are excluded. Images without a readable local file, valid dimensions or a recognizable image header remain unavailable rather than being guessed.

What to do: Keep a backup, compress a copy with a trusted image-optimization tool, and compare the result with the original at normal viewing size. Replace the source only when the reduction is worthwhile and the visual quality, transparency and other required image features are preserved. Run the audit again after replacing the image.

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.

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.

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.

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.

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.

Severity: Info

What it means: The trimmed alt text contains more than 125 Unicode characters. This is a review heuristic, not a standards-based legal or technical maximum.

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.

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