Free practical development guides
Open exercises for completing small web-development tasks. Read the full text and code without buying a course, with assumptions and limits alongside each example.
Free exercises you can follow without signing in
Read the examples and expected results, then run them yourself.
- Verify a JavaScript change with a failing example and eight checksFix a percentage calculation, define its input contract, and run an independent check before putting it into a website.
- Prepare a web image: dimensions, format, and a visible quality checkWork through a 2400 × 1600 photo, choose an output size, compare formats, and check the result before replacing your original.
Publishing and corrections
Quokka Labs publishes these exercises. We distinguish illustrative numbers from execution results and link supporting documentation. Each article carries its content revision date. Check the stated tool and runtime assumptions when your result differs.
For corrections, send the article URL, environment, reproduction steps, and expected versus actual result. Do not include private files or credentials. dante@quokkalabs.net
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