The API
Every page is also JSON. Put /api in front of the address.
GET /api/1990/100 — £100 in 1990 today: result, multiplier, what it buys, houses and wages, and a card URL.
GET /api/1990/100/2005 — between two years. Add ?series=cpi for CPI.
GET /api/income/40000 and /api/income/40000/net — the full tax breakdown, marginal rate, employer cost and income percentile.
GET /api/nhs/1000000 — how long it lasts, and the same sum against every other budget.
GET /api/series — the raw annual tables behind the inflation pages.
No key. No rate limit for now. Responses carry cache headers and the data changes monthly, so cache freely.