Describe the steps in plain English, or paste code you already have. AlgoGraphia draws the chart with the proper shapes — then lets you walk through it, or run it with real values and watch the loops turn.
Free with a Horizech account.
You write:
Read a number n. If n divides by 2, print “even”. Otherwise print “odd”.
Plain English, pseudocode or real code. There is no syntax to learn and nothing to install.
The proper shapes, laid out automatically, with every branch labelled. Export it or share the link.
Step through the boxes, or do a dry run with real values and watch the loop go round.
A flowchart on its own is a picture. The point of this one is that you can run it.
Describe the algorithm in your own words, or paste a function in any of sixteen languages. Pasted code is charted as written — bugs included — because that is usually the thing you are looking for.
Walk the chart one box at a time. At each diamond you choose which way to go, so you can follow both branches of the same decision and see where they rejoin.
Enter the numbers when the chart asks for them, and it works the rest out itself. Loops actually iterate, variables update as you step, and a counter shows how many times each box has been visited.
Drop the chart straight into a worksheet, a report or a slide. SVG stays sharp at any size; PNG is the one to paste when you just need it to work.
The whole diagram travels inside the URL. Nothing of ours has to keep storing it, so the link you hand out today still opens the same chart in years to come.
Flowcharts use a small, standard set of symbols, and the shape is what carries the meaning — which is why these read correctly even in black and white. AlgoGraphia draws all four.
Where the algorithm starts and where it stops. Every chart has exactly one start.
A step that does something — a calculation, or assigning a value to a variable.
A question with two answers. Two arrows leave it, labelled — usually Yes and No.
Reading a value in, or printing one out. This is where a dry run stops to ask you for numbers.
A flowchart is a picture of an algorithm. Each step is a box, and arrows show the order they happen in. The shape of a box tells you what kind of step it is: an oval starts and ends the chart, a rectangle does something, a diamond asks a question with two answers, and a parallelogram reads input or prints output.
No. Plain English is fine — "read a number, keep halving it until it reaches one, count how many times" is enough. If you already have code in C, C++, Java, C#, Python, JavaScript or a dozen other languages, paste that instead and pick the language.
No, and that is deliberate. When you paste code, the chart shows what the code actually does, including the bugs. A corrected diagram would hide the off-by-one you are trying to find.
A dry run walks the chart with real values instead of imagined ones. When it reaches a step that reads input, it asks you for the numbers, then works out every decision from those values — so a loop really iterates and you can watch each variable change.
Yes. The Share button copies a link that carries the whole diagram inside it. There is no database behind it and nothing expires, so a link pasted into a worksheet still opens years later. Opening one asks for a Horizech sign-in first.
Yes, a free Horizech account. Drawing a chart uses a shared AI allowance, so sign-in is what keeps one runaway script from using up everyone's for the day. Reading this page needs no account.
Start from one of the built-in examples, or write your own. Sign in with your Horizech account and it opens straight away.
Open the editor