Pseudocode IDE
<- for ←
Cambridge pseudocode, written and run
Write a program, run it against test cases you cannot see, then read the trace line by line until you find the step that was wrong. Built for IGCSE 0478 and AS & A Level 9618.
Your learning work stays in this browser. No account is required, and the tools keep working with the network off.
What it does
- An editor with syntax highlighting, live error checking and breakpoints.
- Marking that runs your program against hidden test cases and reports what each one did.
- A name for the mistake when you get one wrong: a boundary slip, negatives left unhandled, a loop that runs one time too many.
- Whatever you get wrong comes back on a spaced schedule until it stops being wrong.
- Structured English, trace tables, flowcharts and logic circuits, converted between each other.
- A local SQL sandbox for practising database DDL and DML without an account or server.
What it covers
For teachers
Students practise in the browser without signing in to anything, and export the evidence for you to read.
How it works
- Send the link. There is nothing to install and no account to create.
- Students take a short diagnostic, then practise against what it found.
- They export JSON or CSV and hand it to you; every row names the course it came from.
- The questions are original, written against published syllabus content.
Where it stops
- Coverage is partial. The list above is counted from the question bank rather than claimed.
- There is no class dashboard, so evidence reaches you as exported files.
- Progress lives in each student's browser and is lost if they clear it.
- None of the questions are past-paper material, and nothing here predicts a grade.
A teacher pilot has not been run, which is why this page carries no adoption figures.
Set up your course
Four questions, about a minute. They decide which syllabus you are marked against and which topics you are shown.
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Which course are you taking?
Required -
Which year do you sit the exam?
Required -
Which level?
Required -
How confident do you feel right now?
OptionalOnly used to pick your first question. It changes nothing else, and you can skip it.
Choose a course to begin.
Where your work is kept
Your answers and progress stay in this browser. They are not sent to analytics, no account is required, and no one else can see your work — including us.
That also means: clearing your browser data, using private browsing, or moving to another device will remove your progress unless you export it first.
Try it before you choose
Change the pseudocode and watch the trace table follow it, line by line. This is the same engine your answers are marked with.
Practice
Question
Your answer
Convert
Turn one representation into another. Nothing here is marked.
Your flowchart
Structured English
Cambridge pseudocode
Trace table
Run the chart to see its trace.
Structured English
Which sentences are understood?
CIE pseudocode
Trace table
Nothing converted yet.
Cambridge pseudocode
Trace table
Run the pseudocode to see every step.
Your trace table
Blank cell means unchanged.
CIE pseudocode
Your flowchart
Flowchart
Nothing drawn yet.
CIE pseudocode
Trace table
Nothing traced yet.
Your question
What your question will do
Write a question, then check it.
Logic
Truth tables with every intermediate step, and the matching circuit.
Boolean expression
Supports AND OR NOT XOR NAND NOR and brackets. Variables are single capital letters A–Z.
Precedence: ( ) > NOT > AND/NAND > XOR > OR/NOR
Truth table
Click "Generate" to see it.
Logic circuit
Click any row of the truth table to send those inputs through the circuit.
Click "Generate" to see it.
SQL Lab
Write and run common DDL and DML in a private, in-memory database. Refreshing or resetting clears the tables.
SQL editor
Supports CREATE TABLE, ALTER TABLE ADD/DROP COLUMN, DROP TABLE, INSERT, SELECT, UPDATE, DELETE and simple WHERE conditions joined with AND or OR.
Result
Run a SELECT statement to see rows.
Database schema
No tables yet.
Progress
Evidence by topic
Review queue
Every attempt
Sync across devices
Optional. Everything here works signed out. Signing in only copies your own progress between your own devices — it is never needed to use anything.
No password. We email you a link; clicking it signs you in.
Signed in as .
Syncing merges both sides: attempts made on either device are kept, never overwritten.
Learning gain
Retention
Slips that keep coming back
How these are worked out
Tell us what you think
Stored on this device and included in the export. Nothing is uploaded from here.
Settings
Stored in this browser only.
Colour theme
Choose the colours you want to write code in.
Who is using this browser
Sharing a computer? Add yourself so your work stays separate. Names stay on this device.
Course
Automatic copies on this device
The last few versions are kept here, and one is taken before anything risky. A damaged record is restored automatically.
Checking how this browser is storing your work…
Your data
Export before changing device, or to hand evidence to a teacher.
About DryRun
The same algorithm can be structured English, pseudocode, a trace table, a flowchart or a logic circuit. Understanding usually breaks when you move between two of them. DryRun lets you move across all five and see where the versions stop agreeing.
Your data
Your learning data stays in this browser. Your code, answers, marks, progress, feedback and keystrokes are not sent to analytics. DryRun uses cookie-free Vercel Web Analytics to count anonymous visits and show broad statistics such as pages viewed, country, referrer, device and browser. It does not receive your code, answers, progress, feedback or keystrokes.
Unless you sign in. Signing in is optional and nothing asks you to. If you do, your progress record is copied to the sync server so your other devices can read it, and your email address is stored so the sign-in link can reach you. Nothing else is sent: no browsing, no keystrokes, no third-party tracking. Delete account and synced data in Progress removes the stored copy and the email address for good; the copy in this browser stays.
Stored: the course you chose, every attempt and its marks, your topic evidence, your review queue, your saved editor program, and any feedback you write. All under dryrun.store.v3 and a few keys beside it, including your colour theme.
The last few versions of your work are kept as automatic copies, and one is taken before anything risky. A damaged record is restored from the newest copy by itself.
If you clear your browser data, switch device or use private browsing, your progress is gone unless you exported it. Settings has Export, Import and Erase. Erasing everything removes the automatic copies too.
Several people can share one browser: add each of them in Settings and they get separate records. Names are labels typed on the device, not accounts.
For schools
Because no learning record leaves the browser, there is no student work for a school to process on our side. Evidence reaches a teacher only when a student exports a file and hands it over.
Check it yourself
The interpreter, the graders, the syllabus data and the progress logic are covered by assertions that run in your browser.
Independence
Independent learning resource, not endorsed by Cambridge International Education.
Cambridge International Education is not affiliated with this project. The syllabus codes say which courses it is aimed at, nothing more. Every question is original, written against publicly listed syllabus content.