Experiments that accidentally became useful. Each one does a single thing — nothing leaves your browser unless you ask it to.
Sample Ratio Mismatch checker for A/B testing. Verify whether your test groups are actually balanced using a chi-squared test.
For data people running experiments.
Use ToolGenerate QR codes for any text, URL, or contact string. Pick a size, download the PNG.
Good for WiFi, links, and scrap-of-paper kind of moments.
Use ToolConvert WebP, AVIF, PNG, TIFF, and more to JPEG with adjustable quality. Runs in-browser.
Useful for email, upload limits, and web prep.
Use ToolResize or crop images with a visual interface. Pick dimensions, select crop area, download the result.
Social-media-ready in a few clicks.
Use ToolTransform a rough prompt into a better one, with presets for Claude, ChatGPT, DALL·E, Gemini, and others.
For getting better answers out of AI.
Use ToolOefen je vermenigvuldiging met een leuk spel! Verdien punten en unlock awards door zoveel mogelijk tafelsommen correct op te lossen binnen de tijd.
Voor kinderen (en volwassenen die willen oefenen).
Speel NuThere's always a half-built thing on the workbench. Got an idea for a tool you wish existed? Let me know.
Learn MoreEach of these started as a problem I kept hitting personally. The rule is simple: make it useful, make it simple, make it free. No sign-ups, no analytics following you around, no data leaving your browser unless it has to.
They double as notebooks for whatever I was learning that week — which is why the set keeps growing in odd directions.