Finance and valuation
Mortgage Cost Calculator
See what the monthly payment hides: front loaded interest, the jump when your fixed rate ends, and what overpaying really buys.
Open →Startup Term Sheet Modeller
See what a round really costs you, from the option pool shuffle to the exit waterfall that decides who gets paid first.
Open →Discounted Cash Flow Valuation
Forecast ten years of free cash flow, discount it back, and see what you would have to believe for the market price to hold.
Open →Peer Multiples Valuation
Value a company against its peers on the multiples that actually fit, with sanity checks for the errors that skew the answer.
Open →Compound Interest Calculator
A calm what if for savings: lump sum, monthly contributions, inflation and time, read in today's money as well as tomorrow's.
Open →Learning and visualisation
How Internet Protocols Work
Watch DNS, TCP, HTTP and TLS actually happen, with packets flying between nodes and every header open to inspection.
Open →Fourier Transforms in Sound
Build sounds from sine waves, watch them decompose in real time, and train a small neural network to classify them.
Open →Trigonometry Visualized
Drag a point around the unit circle and watch sine, cosine and tangent trace out as waves, with guided lessons.
Open →Chi-Square Test Calculator
Upload a CSV or Excel file, or type your data, and get p values, critical values and the distribution plotted instantly.
Open →Chi-Square Testing Explained
Learn hypothesis testing through worked scenarios like genetics and fair dice, with tutorials that build the intuition first.
Open →How Tariffs Affect Markets
Simulate supply and demand under tariffs, and see where deadweight loss and surplus actually land, with guided scenarios.
Open →AI and Engineering Productivity
Experimental visualisations of how AI is reshaping engineering work at Anthropic, from velocity to organic metaphors.
Open →Utilities
Markdown Viewer and Exporter
Read any Markdown file rendered, with tables, KaTeX and Mermaid, then save it as PDF or HTML. Nothing leaves your device.
Open →MCP Server Inspector
Paste any remote MCP server URL and get a clean, shareable reference of every tool, resource and prompt it exposes.
Open →PDF Merge & Split
Combine PDFs into one or split a file at chosen page numbers, entirely in your browser. Files are never uploaded.
Open →