Your decisions. Your data. Your engine.
The big calls of a life — quitting, moving, buying, betting on yourself — deserve the same rigour a boardroom gets. LEXUN gives you exactly that: the identical engine organisations use, running free in your browser, on evidence you control, with answers you can reproduce.
What you get, free
LEXUN began as decision infrastructure for organisations. The engine underneath never cared who was asking — so the same three life models organisations pay to wrap in audit trails run for you, in your browser, free.
Cash runway
How long your money lasts, as a probability band across five thousand simulated months — not one hopeful average.
Career change
Whether you can afford the move: the savings bridge, the retrain gap, and the probability your buffer survives the income gap. Not whether you get the job — no defensible base rate for that exists.
Major purchase
House, car, wedding, year off — what the commitment does to your survival band before you sign anything.
Every receipt
Each result carries a seed, a model version and a reproducibility ID. Re-run it with the same model version, inputs and seed: identical output — which is why old model versions are kept available, and why a receipt names its version.
How a run works
1 · Say it in plain English. "I have £14,000 saved and want to quit in March" — the engine frames it into a decision with a horizon and a success criterion.
2 · Sort facts from assumptions. Your bank balance is a fact. Your expected freelance income is an assumption. The engine treats them differently and tells you which one moves the answer.
3 · Get a band, not a verdict. "60–70% probability your plan survives" is what the evidence supports. If the evidence is too thin, the engine refuses to answer rather than inventing a number — the refusal is the feature.
4 · Keep the receipt. Sensitivity analysis names the input to fix; the reproducibility ID lets anyone — including future you — rerun the exact computation.
Private by architecture, not by promise
Your numbers stay here
The engine is JavaScript running on your device. Your salary, savings and plans are computed where you typed them — the engine has no server in the loop, so there is no server-side copy of your figures.
No account with us
Saving decisions uses a LEXUN Key — a passcode that encrypts the record in your own browser storage. We could not read your decisions if we wanted to; that is checkable in the source, not a policy sentence.
The security page and privacy notice describe this architecture in full — including its limits.
What stays free, and what costs money
Free, forever: the three decision models, all 21 templates, reproducible seeded simulation, sensitivity analysis, the adversarial challenge, local saving with a LEXUN Key, and full export of your own data. That is the whole decision loop — not a teaser.
Paid, honestly: the paid tiers on the pricing page fund the free engine. They buy convenience and hosted capability — not better answers. The maths is identical on every tier, because selling a "more accurate" tier would mean the free one lies.
Start now
No signup wall, no card, no trial clock. Open the engine, run a decision that has been sitting in your head, and see what the evidence actually supports.