27 steps — identity, fields, indexing/slicing, pipes, map/select/reduce, group_by, recursive descent, and a capstone exercise.
Interactive Tutorials
Runs in your browser
No account required
Every tutorial here works the same way: you get a real input and an expected output, you type the expression or statement, and we check it against the tool's actual engine — not a canned answer key. No account, no setup, and progress is tracked as you go.
Tutorials in this collection
11 steps — literals, character classes, quantifiers, anchors, alternation, and capturing/named groups.
7 steps — CREATE TABLE, INSERT, SELECT, UPDATE, and a JOIN, run against a real in-browser SQL engine.
8 steps — identity, field/index access, array and string slicing, and deep scan.
6 steps — nodes, edges, and attributes (shape, color, labels) in the DOT language.
Practical guides
Query and transform JSON on the command line with jq.
Learn JSONPath selectors with runnable examples.
Review readable INNER, LEFT, RIGHT, and FULL OUTER JOIN queries.
Continue exploring
Playgrounds
Free-form editors for jq, SQL, regex, Graphviz, and more.
JSON tools
Format, diff, convert, and inspect JSON.
Interview Prep
Practice coding problems in Go, Java, and Rust.
Content reviewed .
