119 tests · 11 categories
Find out what you actually know.
Every test starts with a short course and ends with a quiz. Missed questions come back with the right answer and why it is right. No account and no timer.
119 tests
- Easy
JavaScript fundamentals
Types, scope and the small surprises the language is famous for.
8 questions6 min - Easy
Python essentials
Syntax, built-in types and the everyday behaviour of the standard library.
8 questions6 min - Hard
Complexity and Big O
How algorithms behave when the input stops being small.
7 questions8 min - Medium
Git in practice
The commands you reach for on a normal working day.
7 questions5 min - Easy
Mental math sprint
Arithmetic you should be able to do without reaching for a calculator.
8 questions5 min - Hard
Logic puzzles
Short problems where the obvious answer is usually the wrong one.
7 questions9 min - Medium
Probability basics
Coins, dice and cards, plus the traps that come with them.
7 questions7 min - Easy
The human body
Organs, systems and what each part is actually doing.
8 questions6 min - Medium
Space and astronomy
The solar system, the scale of it, and the forces holding it together.
8 questions7 min - Easy
English grammar
The rules that decide whether writing reads as careful or careless.
8 questions5 min - Medium
Word meanings
Words that turn up often in writing and are often used loosely.
7 questions6 min - Medium
Trading stocks
Shares, orders, costs and risk, in the plain language the industry avoids.
8 questions7 min - Medium
Physics basics
Motion, forces, energy and waves, and the units that hold them together.
8 questions7 min - Easy
Understanding AI
What machine learning actually does, what a language model is, and where both fall down.
8 questions7 min - Medium
Engineering basics
Loads, materials, mechanisms and circuits, and the habit of designing for failure.
8 questions7 min - Medium
Data analysis
Averages, spread, correlation and the traps that make numbers say the wrong thing.
8 questions7 min - Medium
SQL fundamentals
Querying, filtering, joining and grouping, and the order the database does it in.
8 questions7 min - Easy
Cybersecurity basics
Passwords, phishing, encryption and the habits that stop most real attacks.
8 questions7 min - Medium
Networking basics
What happens between typing an address and the page arriving.
8 questions7 min - Medium
Linux and the command line
Files, permissions, pipes and processes, from a shell prompt.
8 questions7 min - Medium
Databases and data modeling
Designing tables that stay correct as the data grows and the requirements change.
8 questions8 min - Medium
APIs and HTTP
Requests, status codes, authentication and the contract between two programs.
8 questions7 min - Easy
Web development fundamentals
HTML, CSS and the browser, and what each one is actually responsible for.
8 questions7 min - Medium
Object-oriented programming
Classes, encapsulation, inheritance and when composition is the better answer.
8 questions7 min - Hard
Algorithms and data structures
Arrays, maps, trees and graphs, and the algorithms that make them useful.
8 questions8 min - Medium
Software testing and debugging
Writing tests worth having, and finding the cause instead of guessing.
8 questions7 min - Hard
System design basics
Scaling, caching, queues and the trade-offs behind every architecture diagram.
8 questions8 min - Medium
Cloud computing basics
Renting computers by the hour, and the bills and habits that come with it.
8 questions7 min - Easy
Computer hardware
What each component does, and which one is actually slowing you down.
8 questions7 min - Hard
Regex challenges
Reading patterns other people wrote, and writing ones you will still understand later.
8 questions8 min - Hard
Code-reading challenges
Working out what unfamiliar code does, which is most of what the job actually is.
8 questions8 min - Medium
Algebra fundamentals
Rearranging, solving and reading what an equation is telling you.
8 questions7 min - Medium
Geometry
Angles, triangles, circles and the handful of formulas worth memorising.
8 questions7 min - Medium
Statistics basics
Summarising data honestly, and knowing what a summary hides.
8 questions7 min - Hard
Calculus intuition
Rates of change and accumulation, explained without the exam technique.
8 questions7 min - Medium
Number patterns
Sequences, series and the rules hiding behind a row of numbers.
8 questions6 min - Medium
Estimation challenges
Getting close on purpose, and knowing when an answer cannot possibly be right.
8 questions7 min - Hard
Deductive reasoning
What follows from what, and the moves that look valid but are not.
8 questions7 min - Medium
Critical thinking
Weighing claims, sources and evidence without either swallowing or dismissing them.
8 questions7 min - Medium
Cognitive biases
The predictable ways judgement bends, and what actually helps.
8 questions7 min - Medium
Scientific reasoning
How claims are tested, why controls exist, and what a result actually shows.
8 questions7 min - Medium
Chemistry basics
Atoms, bonds and reactions, and why the periodic table is arranged that way.
8 questions7 min - Medium
Biology and genetics
Cells, DNA and inheritance, from the molecule to the family tree.
8 questions7 min - Medium
Evolution
How populations change, and the misunderstandings that make it seem stranger than it is.
8 questions7 min - Medium
Electricity and circuits
Voltage, current and resistance, and reading a circuit that actually works.
8 questions7 min - Hard
Mechanics
Forces, motion and equilibrium, worked the way engineers and physicists actually use them.
8 questions7 min - Hard
Thermodynamics
Heat, work and the two laws that decide what is possible.
8 questions7 min - Easy
Earth science
Rocks, plates and the slow processes that shaped everything you can see.
8 questions7 min - Medium
Climate and weather
What makes weather happen, and how climate differs from it.
8 questions7 min - Medium
Materials science
Why steel bends, glass shatters and plastic creeps, and how to choose between them.
8 questions7 min - Medium
Robotics basics
Sensing, deciding and moving, and why the last one is the hard part.
8 questions7 min - Easy
How machines work
Levers, gears, engines and the everyday devices built from them.
8 questions7 min - Easy
Personal finance
Budgeting, debt, savings and insurance, in the order they usually matter.
8 questions7 min - Medium
Investing fundamentals
Assets, risk, fees and time, explained as mechanics rather than tips.
8 questions7 min - Medium
Accounting basics
Debits, statements and why profit is not the same as cash.
8 questions7 min - Medium
Economics
Prices, incentives, growth and inflation, without the political arguments attached.
8 questions7 min - Easy
Business fundamentals
How a business actually makes money, and the parts that decide whether it survives.
8 questions7 min - Medium
Entrepreneurship
Testing an idea cheaply, and what the survivors did differently.
8 questions7 min - Easy
Marketing basics
Positioning, channels and measurement, rather than slogans.
8 questions7 min - Medium
Negotiation
Preparation, interests and the moves that make agreement more likely.
8 questions7 min - Hard
Reading financial statements
Working out what a company is really doing from the numbers it publishes.
8 questions8 min - Medium
Compound interest challenges
Growth that feeds on itself, worked through in numbers you can check.
8 questions6 min - Medium
Risk and return
What risk actually means, how it is measured, and what you are paid for taking it.
8 questions7 min - Medium
Machine learning basics
Training, testing and the workflow behind a model that actually works.
8 questions8 min - Hard
Neural networks
Layers, weights and backpropagation, explained without the linear algebra.
8 questions8 min - Medium
Generative AI
Models that produce text, images and audio, and what that changes.
8 questions7 min - Medium
Prompt engineering
Getting useful output reliably, and knowing when the prompt is not the problem.
8 questions7 min - Easy
AI myths and facts
Sorting what these systems do from what headlines claim they do.
8 questions6 min - Medium
AI safety and ethics
Present harms, disputed long-term risks, and who is accountable.
8 questions7 min - Medium
Data visualization
Choosing a chart that answers the question and does not distort the answer.
8 questions7 min - Hard
Statistics for data science
Sampling, inference and experiments, aimed at people who will act on the answer.
8 questions8 min - Medium
Spot the misleading chart
The tricks that distort a chart without a single false number.
8 questions6 min - Medium
Correlation and causation
What it takes to move from things move together to one causes the other.
8 questions7 min - Medium
Data interpretation challenges
Reading tables and figures and drawing only the conclusions they support.
8 questions7 min - Medium
Spelling challenge
The words that catch people out, and the patterns behind them.
8 questions6 min - Medium
Vocabulary in context
Working out what an unfamiliar word means from the sentence around it.
8 questions7 min - Easy
Commonly confused words
Pairs that sound alike or look alike, and a test for each one.
8 questions6 min - Medium
Reading comprehension
Finding the argument, the evidence and the assumption in what you read.
8 questions8 min - Medium
Sentence correction
Spotting the error in a sentence, and knowing which rule it breaks.
8 questions7 min - Easy
Punctuation
What each mark does, and the handful of rules that prevent most errors.
8 questions6 min - Medium
Writing clarity
Making writing easier to read without making it simplistic.
8 questions7 min - Medium
Analogies
Finding the relationship between two words and applying it to another pair.
8 questions6 min - Easy
Idioms and expressions
Phrases whose meaning cannot be worked out from the words in them.
8 questions6 min - Easy
Communication skills
Being understood, and understanding what other people actually mean.
8 questions7 min - Medium
Public speaking basics
Preparing, delivering and surviving a talk, without pretending nerves do not exist.
8 questions7 min - Easy
Psychology basics
What the field actually studies, what it has established, and what did not replicate.
8 questions7 min - Medium
Memory and learning
How memory works, and which study methods the evidence actually supports.
8 questions7 min - Medium
Decision making
Making better choices under uncertainty, and judging them fairly afterwards.
8 questions7 min - Easy
Emotional intelligence
Recognising and working with emotions, stated carefully rather than as a personality claim.
8 questions6 min - Medium
Social psychology
How people behave around other people, and which classic findings survived scrutiny.
8 questions7 min - Easy
Habit formation
Building and breaking habits, with the numbers stated accurately.
8 questions6 min - Medium
Personality psychology
What personality research supports, and why the popular type tests do not.
8 questions6 min - Medium
Brain basics
Neurons, regions and plasticity, and the neuromyths that will not die.
8 questions7 min - Medium
Perception and optical reasoning
Why seeing is inference, and what illusions reveal about the process.
8 questions6 min - Easy
First aid basics
What to do in the first minutes. General information, not a substitute for training.
8 questions7 min - Easy
Nutrition basics
What the evidence broadly agrees on, and how to read the claims that surround it.
8 questions7 min - Easy
Digital literacy
Understanding the devices, files and services you use every day.
8 questions7 min - Easy
Internet safety
Staying safe online, for yourself and for the people you look after.
8 questions6 min - Easy
Spotting scams
The patterns behind fraud, and the pause that stops it.
8 questions8 min - Easy
Passwords and account security
Why length beats symbols, and what two factor actually stops.
8 questions8 min - Medium
Maps and navigation
Reading a map, taking a bearing, and knowing what GPS cannot tell you.
8 questions8 min - Easy
Time management
Prioritising, estimating and protecting attention.
8 questions8 min - Easy
Workplace communication
Writing clearly, giving feedback and running the conversation.
8 questions8 min - Medium
Basic legal literacy
How contracts, courts and rights work, in general terms.
8 questions9 min - Easy
Consumer rights
Refunds, warranties, chargebacks and getting a complaint taken seriously.
8 questions8 min - Easy
Everyday economics
How prices, wages, interest and taxes show up in ordinary decisions.
8 questions8 min - Medium
World geography
Continents, oceans, rivers and the physical shape of the planet.
8 questions8 min - Medium
Countries and capitals
Capitals that catch people out, and why some countries have several.
8 questions7 min - Medium
World history
The long arc, from farming and cities to empires and revolutions.
8 questions9 min - Medium
Ancient civilizations
Mesopotamia, Egypt, Greece, Rome, China and the Americas.
8 questions8 min - Medium
Modern history
From the age of revolutions to the world after 1991.
8 questions8 min - Medium
Inventions and discoveries
What changed the world, and why credit is rarely simple.
8 questions8 min - Medium
Famous scientists
Who worked out what, and what they actually got wrong.
8 questions7 min - Medium
Art and architecture
Movements, materials and how to look at a building.
8 questions8 min - Medium
Music basics
Pitch, rhythm, keys and why some chords feel unresolved.
8 questions8 min - Medium
Literature
Forms, movements and the tools for reading closely.
8 questions8 min - Medium
Mythology
Greek, Norse, Egyptian and beyond, and what myths were for.
8 questions8 min - Medium
World religions
Beliefs, texts and practices of the major traditions, described neutrally.
8 questions9 min - Easy
Flags of the world
Design rules, recurring symbols and the flags people mix up.
8 questions7 min