Level 1
Lesson 05
Meet POUR
Four simple principles that organise the Web Content Accessibility Guidelines (WCAG).
- About 8 min
- No experience needed
Learning goal
By the end of this lesson you should understand:
- 1.What POUR stands for.
- 2.What each principle asks in plain language.
- 3.How each principle shows up in a real situation.
- 4.How to start recognising POUR in the wild.
Lesson 5 of 10
Section 5.1 · Introduction
Meet POUR
Accessibility can feel like a huge list of rules.
POUR gives us a simpler way to think about them.
P — Perceivable
Can people perceive the information?
O — Operable
Can people interact with it?
U — Understandable
Can people understand it?
R — Robust
Can different technologies work with it?
POUR stands for four principles that organise the Web Content Accessibility Guidelines (WCAG).
Section 5.2 · P is for Perceivable
Perceivable
Information needs to be presented in ways people can perceive.
Real situation
Video without captions
A video contains important spoken information, but there are no captions.
Someone who cannot hear the audio may miss important information.
And for everyone else
Captions can also help someone watching a video in a noisy place — or somewhere they need to stay quiet.
Perceivable = Can I access the information?
Section 5.3 · O is for Operable
Operable
People need to be able to navigate and interact with a website or app.
Real situation
A button that only works with a mouse
A control can be clicked with a mouse, but the keyboard never reaches it.
Someone who uses a keyboard may not be able to use the button.
And for everyone else
Keyboard access can also help someone with a broken mouse, temporary mobility limitations, or someone who prefers keyboard navigation.
Operable = Can I use it?
Section 5.4 · U is for Understandable
Understandable
Information, instructions, and interactions should be clear and predictable.
Real situation
A confusing error
Clear messages help people understand what happened and what they can do next.
Confusing error
Error 40982
More helpful
Your password is incorrect. Please try again.
“Error 40982” tells the person that something went wrong, but not what to do about it.
And for everyone else
Clear and predictable experiences can help people with cognitive and learning disabilities — and make websites easier for everyone.
Understandable = Can I understand what is happening and what to do?
Section 5.5 · R is for Robust
Robust
Websites should be built so that different browsers, devices, and assistive technologies can understand and interact with the content.
Real situation
Someone using a screen reader
Someone might use a screen reader to access a website.
Properly built web content helps assistive technologies understand the information and controls on the page.
If a control is not built in a way assistive technology can interpret, the person may not know it exists or what it does.
And for everyone else
Robust content also keeps working across older devices, new browsers, and settings nobody planned for.
Robust = Can different technologies work with it?
Section 5.6 · Recap
POUR at a glance
Perceivable
Can I perceive it?
Operable
Can I use it?
Understandable
Can I understand it?
Robust
Can different technologies work with it?
POUR isn’t four separate boxes. Together, these principles help us think about making digital experiences more accessible.
Section 5.7 · POUR detective
Spot the principle
You’ve learned the four principles. Let’s see if you can spot them in the wild.
0 of 4 scenarios matched.
Lesson 5 takeaways
By now, you should know:
- POUR organises WCAG into four principles.Perceivable, Operable, Understandable, Robust.
- Perceivable asks: can I access the information?Captions, text alternatives and other ways to take the content in.
- Operable asks: can I use it?Every control should be reachable and usable, including by keyboard.
- Understandable asks: can I understand what to do?Clear language, predictable behaviour, and errors explained in words.
- Robust asks: can different technologies work with it?Content built so browsers, devices and assistive technologies can interpret it.
- POUR is a way of thinking, not a compliance checklist.This lesson introduces the principles — it does not cover full WCAG conformance.
Explore the sources
Explore the sources
This lesson is an introduction to the POUR principles written in our own plain language, based on the material below. It does not teach complete WCAG conformance.
Official standards and resources
Official standard or resource
W3C — WCAG 2.2(opens in a new tab)The official specification, organised around the four POUR principles.
Official standard or resource
W3C — How to Meet WCAG (Quick Reference)(opens in a new tab)The official quick reference, grouped by principle.
Official standard or resource
W3C — Web Accessibility Initiative(opens in a new tab)The home of the group that develops the accessibility standards.
Official standard or resource
W3C — Web Accessibility Perspectives(opens in a new tab)Official short videos: essential for some people, useful for everyone.
Supplementary learning resources
Supplementary learning
WebAIM — Introduction to Web Accessibility(opens in a new tab)Supplementary beginner-friendly overview of the principles.
Supplementary learning
Deque — Web Accessibility Resources(opens in a new tab)Supplementary practitioner explanations and examples.
Supplementary learning
NCADEMI — Accessibility Basics(opens in a new tab)Supplementary plain-language basics for newcomers.
Supplementary learning
Kiddle — Accessibility facts for kids(opens in a new tab)Supplementary very simple explanation of accessibility.
Section 5.8 · Connect POUR to real life
You’ve met POUR.
But accessibility isn’t something we only think about when reading WCAG.
It’s part of everyday digital life.
Coming next — Lesson 6
Accessibility in Everyday Life — Practice
You’ll see how accessibility affects real-world situations — from shopping and education to healthcare, work, mobile devices, and everyday technology. Then you’ll get to practice making accessibility decisions yourself.