工夫 · kufū · the art of making things work

Small, sharp tools for developers.

A hub of developer-focused utilities built to solve small, everyday needs.

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Get a unique URL that captures any incoming HTTP request in real-time. Inspect headers, bodies, and query params as they arrive.

See the public IP address your connection is coming from. Plain-text and JSON endpoints make it scriptable from the command line.

Check my IP

Paste ugly JSON and get it properly formatted.

Format JSON

Learn Git by doing, in a terminal that can't hurt you. Make your first commits, watch the history grow, and dive right in.

Drop a screenshot into a browser or terminal window, or fill the screen with a solid color. A clean stage for shots and recordings.

Open background

Take a quick break with a cartoon rock-paper-scissors showdown. Five seconds, three moves, and one mischievous rival. First to two wins.