Write it.
Draw it.
Run it.
Describe an algorithm in your own words, or paste the code. AlgoGraphia draws the flowchart — and then lets you run it, so the loops stop being a picture and start being a mechanism.
How it works
From a sentence to something you can run.
Most flowchart tools ask you to draw the boxes yourself, and the ones that don’t hand you a picture and stop there. This one does neither.
Plain English is enough — “read a number, keep halving it until it reaches one, count the steps”. Or paste a function in any of sixteen languages and skip the describing.
The chart comes back in the proper notation — oval, rectangle, diamond, parallelogram — laid out automatically with every branch labelled. Export it as PNG or SVG, or copy a link.
Step through one box at a time and choose your own way through each decision, or do a dry run: enter the values when the chart asks for them and let it work the rest out.
Details
Built for someone who is still learning.
A teaching tool is judged on what it does when it is unsure. These are the choices that follow from taking that seriously.
It reads the chart itself and works out each decision from the values you entered, so a loop runs the number of times it really runs. A model asked to predict that would sometimes be confidently wrong, and a learner cannot tell a wrong answer from a right one — which is the whole reason they are looking at it.
If a step is written in a way it cannot read, it stops and asks you which way to go, or offers to skip — and says that later values may then be wrong. An answer that might be invented is worse than no answer.
Paste code and the chart shows what the code actually does, not what it was meant to do. A tidied-up diagram would hide the off-by-one you opened it to find.
Colour is the second signal, never the first, so a chart still reads correctly printed in black and white, photocopied for a class, or by anyone with colour-vision deficiency.
Sharing puts the entire chart inside the URL — there is no database behind it and no id to expire. A link pasted into a worksheet still opens the same chart years later.
Steps you have already visited stay lit and carry a counter, so going round a loop three times looks like going round three times rather than like the chart flickering.
Free with a Horizech account
Draw your first flowchart.
It runs in the browser, on the same Horizech account you already use for everything else we make. Start from one of the built-in examples — bubble sort is the one worth running.