Practical learning for electronics and software

Learn technology through clear, practical examples.

Explore browser-based developer tools and step-by-step lessons in programming and electronics. Follow worked examples and know what each tool or lesson can—and cannot—do.

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Created by Amit Kumar Das · Meet the founder

Learn with purpose

A practical way to learn technical topics

Build understanding with focused explanations, examples you can follow, and tools that state their limits.

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Start with the idea

Understand the core concept and the assumptions behind it before adding complexity.

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Follow a worked example

See sample inputs, expected results, and explanations that connect the steps to the outcome.

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Know what to trust

Check each tool's privacy and limitations, then verify examples in the environment where you plan to use them.

Build and check

Free browser-based developer tools

Format SQL and JSON in your browser. Your input stays on your device.

Free browser-based tool

Format SQL online

Beautify SQL with selectable dialect, indentation, and keyword case. The formatter changes layout, not query logic.

Open the SQL formatter

Related lesson: SQL INNER JOIN vs LEFT JOIN.

Free browser-based tool

Format and validate JSON

Check JSON syntax, format valid data, and get readable parse errors. Your input stays in your browser.

Open the JSON formatter

Related guide: Common JSON syntax errors.

Free browser-based tool

Encode or decode URL components

Convert text for use as one URL component, or decode percent-encoded text. The tool does not process a complete URL.

Open the URL encoder and decoder

Includes examples for spaces, reserved characters, plus signs, and Unicode.

Looking for a particular tool?

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Learn by example

Practical tutorials and guides

Follow step-by-step lessons with sample data, expected results, and clear explanations.

SQL · Step-by-step tutorial

Learn SQL INNER JOIN and LEFT JOIN

Compare join results using a small customers-and-orders dataset, with expected rows and explanations of unmatched records.

Read the SQL joins lesson

Practice formatting with the online SQL formatter.

JSON · Debugging guide

Find and fix common JSON syntax errors

See how missing commas, trailing commas, unquoted keys, and mismatched brackets make JSON invalid.

Read the JSON syntax guide

Check your input with the online JSON formatter.

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