Revision Tools
Dedicated tools for the most calculation-heavy parts of GCSE and A Level Computer Science.
Binary/hex/denary converter, two's complement, bit shifts, file size calculator, and ASCII table.
Open tool →Toggle inputs and see outputs live. AND, OR, NOT, NAND, NOR, XOR, XNOR — with truth tables.
Open tool →Bubble sort, insertion sort, linear search, binary search — animated step-by-step with live trace tables.
Open tool →Complete trace tables for pseudocode programs. Check your answers against worked solutions.
Open tool →Days until your Computer Science exam — AQA, OCR, Cambridge, Eduqas. With revision timeline advice.
Open tool →Rate your confidence on every spec statement for all 6 boards. Saves automatically — no login needed.
Open checklist →Generate timed mock exams from 800+ questions. Pick your board, difficulty and question count.
Generate a mock →Define states and a transition function, load an input tape and step through execution. AQA A Level 3.2.
Open simulator →Build finite state machines, add states and transitions, then test strings step-by-step. AQA A Level 3.2.
Open simulator →Little Man Computer simulator. Write LMC assembly, step through execution and watch all 100 mailboxes update live.
Open simulator →Full AQA A Level instruction set: LDR, STR, ADD, SUB, MOV, CMP, branch, bitwise and shift operations. Registers R0–R12.
Open simulator →Write and run Python 3 in your browser. No installation needed — perfect for GCSE practice and experiments.
Open playground →Write and compile C# in your browser. Great for A Level NEA practice without needing Visual Studio.
Open playground →