Guide · Accessibility
Accessibility & Mobile: Legal Duty and SEO Lever
The BFSG and mobile SEO share most of the work
Since 28 June 2025, the German Accessibility Strengthening Act (BFSG) has obliged most online shops and B2C service providers to run accessible websites. The side effect: a large share of the roughly 50 WCAG 2.1 AA criteria – alt texts, heading hierarchy, contrasts, clean HTML – overlaps with what Google checks in mobile evaluation anyway. Whoever rebuilds now handles two construction sites in one project.
Who the BFSG affects – and who falls outside
The German Accessibility Strengthening Act (BFSG) has applied since 28 June 2025 to products and services aimed at consumers: almost all online shops, plus booking flows, appointment scheduling and order forms. Pure B2B is generally not covered.
The most important exception: micro-enterprises with fewer than 10 employees and at most 2 million euros in annual turnover or balance sheet total are exempt for services. Whether you fall under the threshold depends on details – have a lawyer check that; this is about the technical part and the search engine side, not legal advice.
For everyone else: market surveillance authorities can demand fixes, and the law provides for fines of up to 100,000 euros. In practice, cease-and-desist letters are likely to be the faster pain. And the need for action is real: 94.8 percent of the 1 million most-visited home pages worldwide showed automatically detectable WCAG 2 violations in 2025 – 51 errors per page on average.
| Metric | Value |
|---|---|
| Home pages with automatically detectable WCAG 2 errors | 94.8 % |
| Errors per home page on average | 51 |
Source: WebAIM Million 2025, analysis of the 1 million most-visited home pages worldwide, as of February 2025.
Where accessibility and SEO are the same work
A large share of the WCAG criteria overlaps with what belongs to on-page optimisation anyway. Six points that serve both at once:
- Alt texts: screen readers read them aloud, Google uses them for image search. An alt text of 5 to 15 words serves both.
- Heading hierarchy: exactly one H1, then H2/H3 without jumps. Assistive technology navigates by heading, Google reads the structure.
- Contrasts: WCAG 2.1 AA demands 4.5:1 for body text and 3:1 for large type.
- Keyboard operation: forces real button and a elements instead of click handlers on divs – exactly this HTML is what Google crawls more reliably.
- Understandable link texts: “To the returns policy” instead of “Click here” – tells screen readers and Google what’s behind the link.
- Clean, semantic HTML: nav, main, table – the shared basis of accessibility and crawlability.
Mobile SEO optimisation is a subset of it
Google indexes mobile-first: what gets evaluated is what your smartphone user sees. Many mobile problems are accessibility problems under a different name:
- Touch targets: tap areas of 48 CSS pixels with 8 pixels of spacing.
- Don’t block zoom: user-scalable=no violates WCAG 1.4.4 (200 % magnification) and worsens use for everyone.
- Font size: below a 16-pixel base font, it becomes unreadable for many on a phone.
- Page experience: layout shifts (CLS) make operation impossible for people with impairments – Google measures the same value in the Core Web Vitals, which are checked as part of technical SEO.
In short: whoever implements their BFSG project cleanly has done a substantial part of the mobile SEO homework on the side. The reverse does not hold.
WCAG 2.1 AA as the audit frame
The BFSG names no pixel values. The practical frame of reference is EN 301 549, which points to WCAG 2.1 AA – around 50 success criteria:
- Test automatically: Lighthouse, WAVE or axe DevTools. Free, done in 10 minutes.
- Assess honestly: automatic tools only find about 30 to 40 percent of violations. A Lighthouse score of 100 does not mean “accessible”.
- Check manually: operate the whole page with only Tab, Enter and arrow keys. Run through the checkout with a screen reader (VoiceOver comes preinstalled on every iPhone).
- Prioritise: checkout and forms first – that’s where the legal and economic risk arises. Then templates, individual pages last.
What it really does for rankings
Straight talk: accessibility is not a ranking factor you flip and then positions rise. The benefit lies in three other places: fine and cease-and-desist risks are avoided. Signals Google measures indirectly improve. And a target group is unlocked: according to the Federal Statistical Office, around 7.9 million people with severe disabilities live in Germany, plus everyone with temporary impairments and everyone over 60.
BFSG rebuild at a workshop supplies shop
“At an online shop for workshop supplies with around 3,000 items, we straightened the heading structure because of the BFSG, backfilled alt texts for the product images and made the checkout keyboard-operable. After three months, mobile visibility was noticeably better – not because of a secret switch, but because the basics were finally right.”
— Viktor Pásztor, SEO freelancer
Common mistakes in accessibility and mobile SEO
Installing an overlay widget and ticking the box
The one-click tools don’t fix the errors in the code. Legally contested, technically insufficient.
Only chasing the Lighthouse score
The test doesn’t see more than half of the WCAG requirements at all.
Stuffing alt texts with keywords
Describe what’s in the image, done.
user-scalable=no in the viewport
An attribute that violates WCAG and worsens mobile use.
“Determining” the micro-enterprise exemption yourself
The classification is often not clear-cut. Have it checked.
Touching the checkout last
That’s exactly where the risk is greatest.
Frequently asked questions on accessibility and mobile SEO
Does the BFSG also apply to B2B shops?
Generally no – the law targets consumer business. But as soon as private customers can order and that isn’t cleanly excluded, the scope is quickly reached. When in doubt, clarify legally; fines of up to 100,000 euros.
Is an accessibility overlay enough?
No. Overlays change nothing about the faulty HTML underneath and cover only a fraction of the roughly 50 WCAG 2.1 AA criteria. The rebuild has to happen in the code.
What does implementation cost?
A first audit with prioritisation is doable in 5 to 10 hours (€100/h). Implementation usually runs through the shop’s developer; it’s accompanied as part of ongoing SEO support from €1,000/month.
Is accessibility a ranking factor?
Not directly. But about half of the measures feed into things Google demonstrably evaluates. Expect indirect effect over months, not an overnight jump.
Viktor Pásztor
Viktor Pásztor is an SEO freelancer in Berlin, has been in digital marketing for over 15 years and manages around 15 client projects in parallel, mostly e-commerce and B2B. He has been working 100 % remotely for more than five years – with WordPress, Shopify, Shopware and TYPO3. More about Viktor Pásztor
Keep reading
On-page optimisation
How structure, alt texts and link texts play together.
Technical SEO
What a crawl finds and what happens afterwards.
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