If Your Website Isn't Accessible, It's Generating Digital Waste

Every time someone visits your website and can't use it, energy is consumed for nothing. The server responds, the images download, the JavaScript executes — and none of it matters, because the person on the other end can't access what they came for.

That isn't a hypothetical. In the UK, 22% of the population — 14.1 million people — are disabled. If your website isn't accessible to them, roughly one in five visits to your site is burning energy with zero return.

We've now audited 437 websites across 41,180 pages. The data tells a clear story: accessibility and sustainability aren't separate concerns. They're the same problem.

89% of the sites we audited have critical or serious accessibility issues. 71% have images missing alt text — images that screen reader users will never see, but that their devices still downloaded.

Here's what surprised us most: the least accessible sites emit 2.5 times more carbon per page view than the most accessible ones.

Sites with more than 20 critical or serious accessibility issues average 0.69g of CO2 per page load. Sites with five or fewer average just 0.28g. That's not a coincidence.

Why inaccessible sites are heavier sites

The same design choices that exclude people tend to be the ones that bloat a page. Auto-playing carousels that duplicate content in the DOM and lack ARIA labels. Hero images without alt text that weigh 2MB each. JavaScript-heavy interactions that break keyboard navigation and add hundreds of kilobytes of code.

When we looked at sites that were both in the heaviest 25% by page weight and the worst 25% for accessibility issues, they emitted 2.4 times more carbon than sites that were light and accessible.

Poor accessibility doesn't just lock people out. It makes your website physically heavier.

The frustration multiplier

There's a hidden cost that no carbon calculator measures. When someone with a disability encounters an inaccessible website, they don't just leave. They try. They reload the page. They attempt a different browser. They zoom in, tab through, try to find the content another way.

Every one of those attempts is another page load. Another DNS lookup, another server response, another set of images and scripts downloaded. The carbon cost of an inaccessible page isn't one page view — it's three or four, all for a task the person may never complete.

At 10,000 monthly visitors, if 22% can't properly use your site, that's roughly 3.9kg of CO2 per month spent on page loads that serve no one. Scale that across the millions of inaccessible websites and the numbers become significant.

Digital waste has a definition

We measure waste as the percentage of a website's total transfer size that serves no functional purpose — unused CSS, redundant JavaScript, oversized images. Across our audits, the average site wastes 32% of its page weight.

But there's a category of waste that doesn't show up in a byte count: functional waste. A perfectly optimised image that has no alt text is waste for every screen reader user. A lightweight carousel that duplicates its content in the DOM for animation purposes — without aria-hidden on the clones — is waste for every assistive technology user. The bytes are small. The exclusion is total.

We found 34 sites with carousel implementations that duplicate content without proper ARIA attributes. The content loads twice, assistive technology reads it twice, and the user gets confused — twice.

What actually fixes both problems

The good news: the fixes for accessibility and the fixes for sustainability are overwhelmingly the same work.

• Add alt text to images. If an image is decorative, mark it as such (alt=""). If it's informational, describe it. Either way, you're forcing yourself to ask whether the image needs to be there at all — and that question alone reduces page weight.
• Remove auto-playing carousels. They're an accessibility barrier (content moves before it can be read), they duplicate DOM content, and they load assets that most visitors never see. Replace them with static content or user-controlled galleries.
• Use semantic HTML. Proper headings, landmarks, and structure mean assistive technology can navigate efficiently — and semantic markup is almost always lighter than the div-soup alternative.
• Audit third-party scripts. Chat widgets, analytics, cookie banners — these are some of the biggest accessibility offenders and the biggest sources of JavaScript bloat. Every one you remove improves both metrics.
• Support user preferences. prefers-reduced-motion and prefers-color-scheme aren't just accessibility features. Reduced motion means fewer animations, which means less GPU work, which means less energy. Dark mode on OLED screens uses measurably less power.

Stop treating these as separate budgets

Most organisations treat accessibility and sustainability as separate compliance exercises. An accessibility audit from one consultancy. A carbon report from another. Two sets of recommendations that never talk to each other.

Our P.E.E.R. audit measures both in a single scan because they're inseparable. A website that scores well for accessibility almost always scores well for emissions. Not because we weight the scoring that way — because the underlying causes are the same.

An accessible website is a lighter website. A lighter website is a lower-carbon website. And a lower-carbon website that 22% of the population can't use is still generating waste.

Accessibility isn't a nice-to-have bolted onto your sustainability strategy. It is your sustainability strategy.

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Based on P.E.E.R. audits of 437 websites and 41,180 pages conducted by OYNK. All emissions calculated using the EcoPigs Methodology v2.0 with Ember 2024 global grid intensity data. Published for Neurodiversity Celebration Week 2026.