Read the Learning roadmap chapter first.

💡 An editor is ready below the article—experiment freely!

Updated: May 31, 2026

Checkbox

📌

Conclusion

Checkbox — free browser-based HTML practice

■ What this exercise teaches Create a checkbox with the label "I agree".

Why it matters in real projects

Checkboxes allow multiple selections. Similar patterns appear daily in code review and production UI work.

Step-by-step workflow

1. Read the guide and understand the goal of "Checkbox" 2. Review the HTML editor pane and start from the starter code 3. Open hints if stuck; compare your diff with the sample solution 4. Click Run and inspect preview/console output 5. Auto-check looks for output containing: checkbox, I agree. 6. After success, continue with adjacent exercises in the same category

Core concept explained

Checkboxes allow multiple selections.

Technical focus

Key HTML elements in this task: label, input.

Hint before you peek at the solution

input type="checkbox" wrapped in a label.

Sample solution walkthrough

The solution uses HTML tags such as label, input. Check nesting and closing tags. Explanation: Checkboxes allow multiple selections. Hint recap: input type="checkbox" wrapped in a label.

Solution code

📝 Sample code

<label><input type="checkbox" name="agree"> I agree</label>

Common mistakes for this exact task

- Skipping the hint: input type="checkbox" wrapped in a label.

Troubleshooting

Q: Preview does not change after Run A: Ensure you edited the HTML pane and clicked Run. Q: Looks correct but check fails A: Auto-check looks for output containing: checkbox, I agree. Look for typos, full-width spaces, or unclosed tags. Q: Console shows errors A: Open DevTools Console and fix bracket/quote mismatches at the reported line. Q: Hard to type on mobile A: Use landscape mode or continue on desktop—the same URL keeps progress in localStorage.

Interview / portfolio tips

- Explain the techniques in "Checkbox" in your own words within 30 seconds - Practice walking through each line of the sample solution on a whiteboard - Be ready to discuss tags: label, input - Mention responsive or accessibility trade-offs - Prepare one alternative approach and why you chose this one

What to do after you pass

Move to the next exercise in the html-advanced track, then continue the learning roadmap at /en/learning/html-basic/.

Keywords

Free hands-on exercise covering Checkbox, html-advanced, elementary, label, input, checkbox—search-friendly guide for Checkbox.

🧪 Try it here — safe to break things

Use the editor below to write code and preview instantly.

Jump to editor

■ Exercise task

Create a checkbox with the label "I agree".

Hint if stuck

input type="checkbox" wrapped in a label.

15pt

Checkbox

Create a checkbox with the label "I agree".

Code

Preview

Errors & Console

Click error to highlight line. ✕=error ⚠=warning ›=log.

Roadmap · All guides

Deep dive

"Checkbox" is a elementary-level HTML exercise. Create a checkbox with the label "I agree". Run it in-browser with automatic checking.

Checkboxes allow multiple selections. Similar patterns appear daily in code review and production UI work.

Pair this with the html-basic roadmap. Exercise #30 reinforces core html-advanced skills.

Step-by-step workflow

Read the guide and understand the goal of "Checkbox"
Review the HTML editor pane and start from the starter code
Open hints if stuck; compare your diff with the sample solution
Click Run and inspect preview/console output
Auto-check looks for output containing: checkbox, I agree.
After success, continue with adjacent exercises in the same category

How to read the sample solution

The solution uses HTML tags such as label, input. Check nesting and closing tags. Explanation: Checkboxes allow multiple selections. Hint recap: input type="checkbox" wrapped in a label.

Real-world & career relevance

Forms power sign-up, contact, and checkout. Proper label/input pairing is required in WCAG accessibility audits.

Common mistakes

Skipping the hint: input type="checkbox" wrapped in a label.
label for and input id mismatch
inputs without name inside form
checkbox without associated label

Troubleshooting

Preview does not change after Run: Ensure you edited the HTML pane and clicked Run.
Looks correct but check fails: Auto-check looks for output containing: checkbox, I agree. Look for typos, full-width spaces, or unclosed tags.
Console shows errors: Open DevTools Console and fix bracket/quote mismatches at the reported line.
Hard to type on mobile: Use landscape mode or continue on desktop—the same URL keeps progress in localStorage.

Interview & portfolio tips

Explain the techniques in "Checkbox" in your own words within 30 seconds
Practice walking through each line of the sample solution on a whiteboard
Be ready to discuss tags: label, input
Mention responsive or accessibility trade-offs
Prepare one alternative approach and why you chose this one

Glossary

form: Container for user input submitted to a server.
label: Describes an input; pair with for/id.
checkbox: On/off selection control.

Keywords covered on this page

Free hands-on exercise covering Checkbox, html-advanced, elementary, label, input, checkbox—search-friendly guide for Checkbox.

Related dev tools

Learning roadmap

Learning roadmap →

Related exercises

Frequently asked questions

Is "Checkbox" free?

This exercise is free and runs entirely in your browser. No account or credit card required.

Difficulty and time?

"Checkbox" is level "elementary". Read the guide first; beginners can usually finish within 30 minutes. Allow 5–15 minutes per exercise. Use hints, then the solution if stuck.

What after a correct answer?

After a correct answer, use "Next exercise". When you finish a category, continue on the <a href="/en/learning/html-basic/">learning roadmap</a>.

Works on mobile?

Works on mobile browsers, but typing code is easier on a desktop.

Where are other exercises?

All exercises: <a href="/en/learn/">/en/learn/</a> with category filters.

Key takeaway for "Checkbox"?

Checkboxes allow multiple selections. Hint: input type="checkbox" wrapped in a label.

Where does HTML Advanced fit?

Forms power sign-up, contact, and checkout. Proper label/input pairing is required in WCAG accessibility audits.

Step-by-step for "Checkbox"?

1. Read the guide and understand the goal of "Checkbox" 2. Review the HTML editor pane and start from the starter code 3. Open hints if stuck; compare your diff with the sample solution 4. Click Run and inspect preview/console output 5. Auto-check looks for output containing: checkbox, I agree. 6. After success, continue with adjacent exercises in the same category

How to read the sample solution?

The solution uses HTML tags such as label, input. Check nesting and closing tags. Explanation: Checkboxes allow multiple selections. Hint recap: input type="checkbox" wrapped in a label.

Something is not working?

Preview does not change after Run → Ensure you edited the HTML pane and clicked Run. Looks correct but check fails → Auto-check looks for output containing: checkbox, I agree. Look for typos, full-width spaces, or unclosed tags. Console shows errors → Open DevTools Console and fix bracket/quote mismatches at the reported line. Hard to type on mobile → Use landscape mode or continue on desktop—the same URL keeps progress in localStorage.

Career / interview angle?

Explain the techniques in "Checkbox" in your own words within 30 seconds Practice walking through each line of the sample solution on a whiteboard Be ready to discuss tags: label, input Mention responsive or accessibility trade-offs Prepare one alternative approach and why you chose this one

Related dev tools?

<a href="/en/tools/html-escape/">HTML Escape</a>, <a href="/en/tools/regex/">Regex Tester</a>

Prerequisites?

Read the <a href="/en/learning/html-basic/">Learning roadmap</a> chapter first.

Can I change the starter code?

Yes—if it works. Understanding the starter first, then adding minimal diffs, speeds up learning.

What do the points mean?

15pt is a difficulty hint, not a score you must maximize.