Interactive Revision Tools

Step-by-step walkthroughs, extended algebraic practice, and exam-style problems with answer checking.

• Basic laws: idempotent, identity, null, complement, double negation
• De Morgan's law, absorption, NAND and NOR equivalences
• Multi-step algebraic simplification practice
• 40 exam-style questions with instant marking

Click to place logic gates and connect them with wires. Signals propagate automatically and a truth table is generated from your circuit.

• AND, OR, NOT, NAND, NOR, XOR gates
• Live signal propagation (0/1)
• Auto truth table + Boolean expression
• Build and test any combinational circuit

Click cells to set 0s and 1s. Groups are found automatically, highlighted in colour, and the simplified Boolean SOP expression is shown instantly.

• 2, 3, and 4 variable K-maps
• Automatic grouping including wrapping groups
• Colour-coded group overlays on the map
• Truth table shown alongside the map

Convert between Binary, Denary, and Hexadecimal in any direction, with every step of the working shown. Not just the answer, but the complete method.

• All 6 conversion directions: Bin-Den, Bin-Hex, Den-Hex
• Division method shown for Denary to Binary and Hex
• Positional value tables for Binary and Hex to Denary
• Direct 4-bit grouping method for Binary-Hex

Animate push, pop, enqueue, and dequeue operations with live colour-coded feedback. Includes a circular queue with front and rear pointer arrows showing wrap-around in real time.

• Stack (LIFO) with push and pop
• Queue (FIFO) with enqueue and dequeue
• Circular queue with wrap-around pointer visualisation
• Overflow and underflow detection

Insert and delete values to build a BST. Watch the tree restructure in real time and animate in-order, pre-order, and post-order traversals node by node.

• Insert and delete with automatic restructuring
• Animated traversal - in-order, pre-order, post-order
• Tree height, balance, min, and max shown live
• Load a built-in example to explore immediately

Insert, search and delete key-value pairs and watch the hash function work step by step. Switch between linear probing and chaining to see how each handles collisions.

• Step-by-step ASCII hash calculation for every operation
• Linear probing: watch slots probe one by one
• Chaining: linked list chains grow visually per slot
• Choose prime table sizes: 7, 11, 13, 17

Toggle O(1), O(log n), O(n), O(n log n), O(n²), and O(2ⁿ) curves on a live chart. Drag the n slider and hover to see exact operation counts at any input size.

• 6 complexity curves drawn on a canvas chart
• Hover crosshair shows exact operations at any n
• Preset views: All, No Exponential, Fast Only
• Algorithm examples and exam tips included

Watch sorting algorithms run step by step with animated bar charts. Compare speeds, track comparisons and swaps, and understand exactly what each algorithm does at every stage.

• Bubble, Insertion, Selection, Merge, Quick Sort
• Play, Pause, and single-step controls
• Comparison and swap counters
• Time and space complexity shown for each algorithm

Step through algorithms line by line and fill in trace tables. Covers sorting algorithms, searching, and exam-style pseudocode questions.

• Bubble, Selection, Insertion Sort
• Linear and Binary Search, Merge Sort
• Fill-in-the-blank with auto-marking
• Exam-style pseudocode questions

Paste Python or C# code and generate a standard flowchart instantly. Useful for converting algorithms into a visual form for exam answers and coursework.

• Supports if/elif/else, for, while loops
• Subroutine (function/procedure) detection
• Export as SVG or PNG
• Follows standard GCSE/A-Level flowchart notation

Draw entity-relationship diagrams with drag-and-drop entities, attributes, and crow's foot notation. Design schemas before normalising or querying them.

• Drag-and-drop entity and attribute creation
• One-to-one, one-to-many, and many-to-many cardinality
• 3 pre-loaded examples: School, Library, Online Shop
• Export diagram as PNG image

Work through realistic database scenarios, identifying and removing anomalies to achieve 1NF, 2NF, and 3NF. Every question is auto-marked with instant feedback.

• 5 real-world scenarios: Orders, Library, School, Hospital, Music
• 49 auto-marked questions across all three normal forms
• Transitive and partial dependency identification
• Progress saved automatically in your browser

Write and run real SQL queries against six different databases, all inside your browser. A full SQLite engine runs locally so nothing is ever sent to a server.

• Six scenarios: Cinema, Library, Hospital, Music, Football, School
• 48 guided exercises from basic SELECT to multi-table JOINs
• Auto-marked with instant correct or incorrect feedback
• Hints and model solutions for every question

Nine interactive networking tools in one place. From the TCP/IP stack to subnet masks, packet switching to DNS resolution - every core networking topic made visual.

• TCP/IP stack with animated encapsulation
• Topology builder with drag-and-drop devices
• Subnet calculator with full binary AND working
• Packet simulator, DNS, HTTP and IP addressing

Explore four encryption methods with full step-by-step working. From classical Caesar shifts to Vernam XOR and a full RSA key generation and encrypt/decrypt walkthrough.

• Caesar cipher with shift slider and full alphabet mapping
• Vigenere cipher with per-character key working table
• Vernam one-time pad with bit-level XOR breakdown
• RSA explorer: choose primes, generate keys, encrypt and decrypt

Write HTML, CSS and JavaScript in a split-pane editor and watch your page update instantly. Download your finished page as a .html file to run locally.

• Separate tabs for HTML, CSS and JavaScript
• Live preview updates as you type - no refresh needed
• External stylesheets via CDN work out of the box
• Five starter templates: blank, Bootstrap, DOM example, form
• Copy to clipboard or download as a standalone .html file

Watch the Fetch-Decode-Execute cycle happen in real time. Animated data packets travel along colour-coded address, data and control buses between every CPU register.

• All 6 registers: PC, MAR, MDR, CIR, ALU, ACC
• Animated packets move along colour-coded buses
• Step mode or auto-play at 4 speeds
• Live RAM panel updates as memory changes
• 3 presets: LDA/ADD/STA, copy, subtraction
• Plain-English description of every micro-operation

Build a Turing machine from scratch or load a preset. Define transition rules, watch the animated read/write head move across an infinite tape, and step through each instruction.

• Infinite tape with animated head movement
• Editable transition rule table
• Live state diagram with current state highlighted
• Presets: unary increment, addition, binary increment, even/odd
• Step-by-step execution log
• Exam tips covering Church-Turing thesis and the Halting Problem