BUILD THIS
What the checks look for
These selected checks run against your rendered page. They do not replace keyboard, visual, accessibility or cross-browser testing.
WEB DEVELOPER MASTERY LAB / FROM MARKUP TO INTERACTION
Write it.
See it.
Make it work.
Build real page elements, test the details and learn how HTML, CSS and JavaScript work together.
● ● ● your-next-website.html
YOUR IDEA, IN THE BROWSERBuilt one skill
at a time.
at a time.
Structure. Style. Interaction.
<HTML>{ CSS }JavaScript()
0 / 50workshop checks passed
body.htmlSaved locally
HTML is a body fragment. JavaScript runs after it is inserted. The preview is isolated and blocks external requests, popups and form navigation. Changes run only when you update or check. Ctrl/⌘ + Enter updates the preview.
Fixed sizes scroll inside this preview area on smaller screens. Width changes alone do not rerun checks.
Preview your page, then run its checks.
JavaScript errors
No errors reported.
Explain your design decision
TEN CHAPTERS / FIFTY PRACTICAL WORKSHOPS
Build a complete set of front-end skills.
All workshops are unlocked. Completion means the listed checks passed once in the chosen viewport; it is not a professional certification.
THE CHECKS A SCRIPT CANNOT FINISH FOR YOU
Review like a web developer.
This checklist is self-reported. Review the current page again after material changes; it is not an accessibility conformance assessment.
Keep building beyond the lab.
Your work, backed up
Drafts, notes and completion checks save in this browser when storage is available. Export before moving devices or clearing site data.
Useful next steps
- Download the 50-workshop handbook
- Practice deeper JavaScript logic
- MDN web development curriculum
- MDN accessibility learning path
Downloaded pages are standalone learning files. Review and test them before publishing. This course covers front-end foundations; servers, databases and production deployment need additional study.