Image SEO Audit

Catch the images
quietly costing you speed and rankings.

One unoptimised hero image can add two seconds to your load time and fail Core Web Vitals on its own. SEOMentor lists every image by filename, size and format, so you know exactly which files to fix.

Free forever · No credit card required

"Optimise your images" isn't actionable

Without SEOMentor

Speed tools tell you to serve images in next-gen formats and properly size them. They rarely tell you which file, on which page, at what size. So you either optimise everything blindly or nothing at all.

With SEOMentor

You get a list: filename, file size, format, dimensions, and whether alt text is present. Sort by size, fix the ten worst offenders, and re-scan to see the speed score move.

What gets audited

Every image found on the page or across the crawl.

File size

Actual bytes per image, so you can find the 890 KB hero that's blocking your LCP.

Missing alt text

Counted and listed. Affects accessibility, image search visibility, and is a common WCAG failure.

Format

Flags JPEG and PNG where WebP would cut size substantially with no visible quality loss.

Unoptimised count

A single number for how many images are larger than they need to be, so you can track it down over time.

Grid and list views

See images visually or as a sortable table, filtered by issue type.

Site-wide view

After a crawl, see image problems across every page rather than one at a time.

One tool, not ten

SEOMentor replaces
your whole SEO stack

Every tool you’d normally juggle audits, rank tracking, backlinks, reporting replaced by one AI that already knows your site.

Product names and logos are trademarks of their respective owners, shown for comparison purposes only. SEOMentor is not affiliated with or endorsed by them.

Powered by the tools
you already trust

Real data from the sources you already use nothing modelled, nothing estimated.

Keywords Everywhere

DataForSEO

PageSpeed Insights

Google Search Console

Google Analytics 4

Claude

Gemini

Keywords Everywhere

DataForSEO

PageSpeed Insights

Google Search Console

Google Analytics 4

Claude

Gemini

Free forever · No credit card required

Product names and logos are trademarks of their respective owners. SEOMentor connects to their official APIs and is not endorsed by them.

How it works

From URL to answer, in three steps

Run a scan or crawl

Images are audited automatically as part of every scan. A crawl extends the audit across all discovered pages.

Filter to the problems

Filter by unoptimised, missing alt, or oversized. The grid shows you the actual images so you can recognise them instantly.

Fix the biggest first

Sorted by file size, the top few images usually account for most of the weight. Fixing those moves your speed score more than anything else.

What you'll find

Specific files, not general advice.

hero-banner.png — 890 KB, PNG, no WebP version. This is your LCP element.

12 images have no alt text, invisible to image search and screen readers.

team-photo.jpg — 1,240 × 960 displayed at 400 × 310, serving 3× more pixels than needed.

44 images total, 18 flagged as unoptimised.

Measured, not estimated

Real file sizes

Images are fetched and measured. Sizes are actual bytes transferred, not predictions.

Tied to speed data

The image audit sits alongside your Core Web Vitals, so the link between a heavy image and a failing LCP is visible in one place.

Re-scan to verify

Compress an image, re-scan, and confirm the size dropped and the score moved.

Related free tools — no signup

Image Alt Checker Page Speed Checker

Works with

Speed & Core Web Vitals

Find exactly what's slowing you down.

Site Crawler

Audit every page at once.

Technical SEO Audit

Every issue, ranked by impact.

All answers to your questions

Does it compress my images for me?

No. SEOMentor identifies which images are a problem and why. Compression happens in your own workflow or CMS, where you control quality settings.

Why does alt text matter for SEO?

It's how search engines understand image content, which drives image search traffic. It's also an accessibility requirement screen readers depend on it.

Should I convert everything to WebP?

For photographs and most site imagery, yes WebP typically cuts file size 25 to 35 percent at equivalent quality, and browser support is effectively universal now. Keep SVG for logos and icons.

What counts as unoptimised?

Images substantially larger than needed for their display size, or in a format where a modern alternative would save meaningful bytes.

Can I check images across my whole site?

Yes. Run a site crawl and the image audit extends across every page it discovers, not just the one you scanned.

Do images really affect rankings?

Indirectly but significantly. They're the most common cause of poor LCP, which is a ranking signal and heavy pages lose visitors regardless of where they rank.