The bench
Tools
Every one of these runs entirely in your browser. Nothing is uploaded, nothing is stored, and none of them need a server. They exist because I got tired of doing the same arithmetic by hand in the middle of writing something else.
Each one shows its working so you can disagree with it.
Security 4
File signature inspector
Runs in your browser · nothing uploaded
Drop a file and compare what the extension claims against what the bytes actually say. Flags RTLO characters, invisible characters, double extensions, and a ZIP appended to another format.
Open tool why I built it
Card number workbench
Runs in your browser · nothing uploaded
Search 12,000 public BIN ranges by bank name, run the Luhn checksum by hand, then hide the digits a photo would hide and name the bank on the logo. A million blind guesses usually come down to a handful. The arithmetic behind why a mirror selfie of your card gives away more than the covered digits suggest. Test numbers only.
Open tool why I built it
DTMF decoder
Runs in your browser · nothing uploaded
Point it at a dial-pad recording (file or microphone) and it reads the digits back. Full 16-key grid, Goertzel under the hood, and a test keypad so you can hear what it hears. Built because one CTF challenge was fifty seconds of beeping and I wanted the flag in forty-nine.
Open tool why I built it
Fødselsnummer explorer
Runs in your browser · nothing uploaded
Decode a Norwegian national ID number, watch the two mod-11 check digits fall out of the arithmetic, and count what survives once you know a birthday. Because the regulation hands numbers out in descending order and SSB publishes how many were born each day, someone born in Norway on a known date is usually one of under a hundred, not one of 100,000.
Open tool why I built it
Chemistry & pharmacology 5
Elemental mineral calculator
Runs in your browser · nothing uploaded
How much magnesium is actually in 400 mg of magnesium oxide, and is the label even chemically possible? Parses any formula, hydrates included, from standard atomic weights.
Open tool why I built it
Half-life & accumulation visualiser
Runs in your browser · nothing uploaded
A one-compartment model that shows why a short half-life makes peaks and troughs swing, and why repeated dosing takes four to five half-lives to plateau. Relative units; a shape tool, not a dosing calculator.
Open tool
Interactive periodic table
Runs in your browser · nothing uploaded
Atomic numbers, shells, masses, groups, and basic chemistry, with a search box.
Open tool
Perturbation framework
Runs in your browser · nothing uploaded
Tick the signs you can actually observe (pupils, sweat, reflexes, gut, speech) and it ranks which drug mechanisms fit and which the evidence argues against. 13 mechanisms, 67 signs, 58 profiles, and a safety note on each one. A thinking tool with unvalidated weights, not a diagnosis.
Open tool why I built it
Faste grenser
Runs in your browser · nothing uploaded
Norway sets statutory blood-concentration limits for 28 substances other than alcohol, in µmol/L, across three tiers. This puts all 28 next to a decay curve, because the number people get wrong is not the limit, it is how long the limit outlasts the effects. Cannot tell you whether it is safe or legal to drive, and says so.
Open tool
Reading & evidence 2
N-of-1 trial designer
Runs in your browser · nothing uploaded
Turns a self-experiment into a real trial: randomised block order from a seed you write down, a washout sized from the half-life, a self-blinding scheme, and a pre-registration you commit to before seeing any data. Tells you when your design cannot reach significance, which is most of the time.
Open tool
Study smell test
Runs in your browser · nothing uploaded
Twelve questions to run against a paper before quoting it: who was studied, how it was designed, what could explain the result instead, and who paid. Produces no score, on purpose.
Open tool why I built it
Nothing in that category.
External tools I use
- ProTox 3.0
Toxicity prediction. A hypothesis generator, not a human safety test. Its output belongs in the "what should I investigate?" column, never the "this is safe" one.
- SwissTargetPrediction
Rough target-prediction exploration. Treat it as a lead generator, not a source of truth.
- CyberChef
The everything-encoder. Runs locally in the browser once loaded.