3.1.5 Reading Level

1. What is the goal of this criterion?

Complex technical text is as much a part of the web as espresso is of a meeting – sometimes unavoidable, but not easy for everyone to digest. People with reading difficulties, cognitive disabilities or those reading in a language other than their first struggle when text is too hard to understand.

The goal of WCAG Success Criterion 3.1.5 is clear: if a text requires more reading ability than is typical after about nine years of school, you need a simpler version or supplemental content that aids understanding.

In short: even complex content should be accessible to as many people as possible – through simpler language or additional support.

2. What exactly does it require?

This criterion covers text that requires reading ability beyond the lower secondary education level. WCAG defines this as the period of education after the first six years of school, ending about nine years after the start of primary school. Proper names and titles are not counted.

If a text goes beyond this level, you need to provide one of the following:

Supplemental content, for example:

• a summary in plain language
• images, graphics or diagrams that illustrate the content
• a spoken version of the text
• a sign language version

Or an alternative version:

• a revised version that doesn’t go beyond the lower secondary reading level

Important note: this criterion is Level AAA – the highest level in WCAG. Especially for technical text it can’t always be met for all content, but it’s a valuable goal.

3. Why does it matter for accessibility?

Imagine having to read a technical article about quantum physics in a language you only half know. That’s how many people experience complex text – even if they’re experts in other fields.

Simpler language and accessible alternatives improve accessibility because they:

• help people with dyslexia or other reading difficulties understand content
• make access easier for people reading in a language other than their first
• allow people with cognitive disabilities to grasp complex topics
• help Deaf people whose first language is a sign language
• reduce stress and make reading more pleasant for everyone

Decoding complicated sentences takes energy that’s then missing for understanding. Short sentences, familiar words and clear structure make reading much easier.

4. How to meet the criterion

The good news: writing clearly is a skill you can learn. Here are some proven tips:

Ground rules for understandable text:

• Write short sentences – as a rule of thumb, no more than 15 to 20 words.
• Use familiar, everyday words instead of jargon.
• Write in the active voice (“The system was developed” → “We developed the system”).
• Break content into short paragraphs.
• Use descriptive subheadings for orientation.

Tools for checking readability:

• for English text, readability formulas such as Flesch-Kincaid or the SMOG index
• for German text, the adapted Flesch index or the Wiener Sachtextformel
• writing tools that highlight long sentences and passive constructions

Formulas only give an approximation. The most meaningful test is with people from your target audience.

Supplemental support:

• Offer summaries in plain language or – for specific audiences – in easy-to-read language.
• Use illustrations, diagrams or infographics.
• Provide an audio version.
• Explain unavoidable technical terms, see Unusual Words.

The difference between easy-to-read and plain language is explained in the article Easy-to-read and plain language.

5. Why this criterion matters for businesses

3.1.5 is a Level AAA criterion and not legally required under the European Accessibility Act, its German implementation the BFSG, or EN 301 549, which requires WCAG 2.1 Level AA. In Germany, however, public sector bodies have a related obligation: the BITV 2.0 requires explanations in German Sign Language and easy-to-read German on the homepage, covering the main content and navigation, among other things. This section is general information, not legal advice.

1. Reach more people

Clear language reaches more people. That applies not only to people with disabilities but also to anyone in a hurry, tired readers or international audiences. Clear communication always pays off.

2. Fewer misunderstandings

Complicated text leads to misunderstandings and drop-offs. Understandable content makes sure your message gets through.

3. Fewer questions

Clear communication reduces follow-up questions and complaints. Clarity pays off especially in terms and conditions, privacy notices and product descriptions.

6. The success criterion in the W3C’s words

Success Criterion 3.1.5 Reading Level (Level AAA)

When text requires reading ability more advanced than the lower secondary education level after removal of proper names and titles, supplemental content, or a version that does not require reading ability more advanced than the lower secondary education level, is available.

In short: if a text – excluding proper names and titles – requires reading ability beyond lower secondary level, supplemental content or a simpler version must be available.