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Performance Audit

Website Image Performance Audit

Review which image assets hurt load time, estimate bandwidth savings, and surface oversized images, missing lazy loading, and outdated formats.

Sync auditCore Web Vitals supportMVP

Analyze runs the actual tool flow for this page. Sync audits use the extractor job API, palette is computed from discovered assets, and screenshot mapping uses a dedicated screenshot job.

Current quota

Plan-aware limit for this tool

This block reads the active user plan when you are signed in. Anonymous visits fall back to current free-plan limits.

Current plan

Website Image Performance Audit

FREE

Quota details are not available for this tool yet.

Report shape

What the website image performance audit page shows

The page is structured like a product screen and a landing page at the same time: overview first, then details, export, API, FAQ, and related tools.

SummaryBiggest OffendersRecommendationsExport

Total image weight

14.2 MB

Combined transfer footprint for discovered assets.

Potential savings

5.8 MB

Estimated from oversized images and format opportunities.

Lazy-loaded images

41%

Share of discovered images using loading=lazy or equivalent.

Modern formats

34%

WebP, AVIF, SVG, or other modern delivery formats.

Performance checks

  • Total transfer size, heaviest files, average image size, and responsive delivery coverage.
  • Images whose natural size is much larger than the rendered footprint.
  • Format opportunities for PNG, JPEG, and duplicate background assets.

Optimization guidance

  • Separates critical, warning, and good findings for triage.
  • Highlights third-party image delivery and CDN concentration.
  • Keeps estimated savings visible in KB and MB.

Performance summary

  • Total images, total payload, potential savings, and modern format share.
  • Largest image, average image, and responsive-image coverage.
  • Hero-image focus for above-the-fold optimization work.

Per-image analysis

  • Transfer size, natural dimensions, displayed dimensions, and compression suggestions.
  • Format suggestions with WebP or AVIF opportunities where relevant.
  • Lazy loading and responsive delivery hints per asset.

Filters

Useful report filters

Critical onlyOversized onlyHeavy files onlyNon-modern formatsNo lazy loading

Use cases

Teams that benefit from this workflow

Frontend and performance teams preparing image optimization sprints.

Site owners looking for the fastest wins before a launch or redesign.

Technical SEO reviews that need concrete asset-level savings estimates.

FAQ

Questions users ask before implementation

Does this replace Lighthouse or WebPageTest?

No. It complements them by focusing specifically on the image layer and turning the image inventory into actionable asset-level recommendations.

How is an oversized image detected?

The audit compares the natural size of the asset to the approximate displayed footprint and flags large mismatches.

Why focus on formats separately from file size?

A file can be small enough and still use a poor format for its content type, so the audit keeps transfer weight and format opportunity as separate signals.

Related tools

Adjacent workflows in the suite

Image SEO Audit

Image SEO Audit Tool

Score image SEO, alt text quality, accessibility gaps, filename quality, and responsive delivery signals.

  • Missing and empty alt checks
  • Duplicate and suspicious alt detection
Sync auditAccessibilityMVP
Open tool

Broken Images

Broken Image Checker

Find image 404s, 403s, 500s, timeouts, redirect loops, malformed URLs, and mixed-content problems.

  • HTTP and network failure detection
  • Broken background-image and srcset validation
Sync auditQA-readyExport support
Open tool

Screenshot + Assets

Website Screenshot and Asset Mapper

Capture screenshots, map image overlays, and connect asset metadata to page coordinates through UI or API.

  • Full-page screenshot capture
  • Overlay mapping for discovered assets
Async jobToken APIVisual audit
Open tool