Flowcharts for C
The university-lab classic: arrays, pointers, three kinds of loops. rombik draws an ISO-5807 flowchart straight from C code.
Free · no sign-up · your chart in seconds
Flowcharts from C code
rombik parses C: functions, if/else, switch-case, for/while/do-while loops. Pointers and the preprocessor don’t get in the way — the engine builds an ISO-5807 flowchart of the algorithm.
int maxOf(int a[], int n) {
int m = a[0];
for (int i = 1; i < n; i++) {
if (a[i] > m) m = a[i];
}
return m;
}How to make a flowchart from C code
- 1 Paste your code
Copy a C function into the editor or drag a file in.
- 2 Get the chart
The engine builds a flowchart to the standard. Toggle to a structogram if you need one.
- 3 Export
Word, Visio, draw.io, Typst, Excalidraw, SVG, PNG or PDF — native shapes, not a picture.
C in rombik: frequent questions
Pointers and pointer arithmetic? +
Drawn as ordinary actions: *p = *p + 1 is one process block. The chart shows algorithm steps, not memory work.
What about #define and #include? +
Preprocessor directives are skipped — they are not algorithm steps. Code with them parses fine.
Is do-while drawn correctly? +
Yes: the condition sits AFTER the body and the arc returns bottom-up — that is how the standard shows a post-test loop.
scanf and printf? +
They become input/output parallelograms — distinct shapes, not plain process boxes.
Drawing flowcharts by hand takes hours
Students — a report, lab, coursework, thesis. Teachers — handouts, lectures, assignments and their examples. Anywhere there is an algorithm, it has to be drawn as a standards-compliant flowchart: rulers, shapes, arrows, redoing it after every code change. rombik does this in a second, and you can adjust the result to any requirements.
Your flowchart — in the format you need
No dead images: your chart arrives in the native format of your tool. In Word and Visio — real editable shapes, in Typst — clean typesetting code, in Excalidraw and draw.io — board objects. Pick any of the eight formats — all standard-compliant.
- Word (.docx) · Visio (.vsdx) — real editable shapes, not a pasted picture
- Typst — clean CeTZ code, native to academic typesetting
- Excalidraw · draw.io — native objects on the board and diagrams.net
- SVG · PNG · PDF — universal: print, slides, the web
#import "@preview/cetz" #cetz.canvas({ rect((0,0), label: "Початок") line((0,0), (0,-1)) diamond(label: "n > 0") })
Nassi-Shneiderman structogram — same code, a different view
Nested boxes, not a single arrow: sequence is a stack, branching is a condition triangle, a loop is a frame. A clean view of the algorithm’s structure, often required in universities. One toggle in the editor — and the same function becomes a structogram.
- One click: flowchart ↔ structogram — from the same code
- Any format — Word, Visio, draw.io, Typst, Excalidraw, SVG, PNG, PDF
- Works the same across every language — nothing to configure
What rombik does
Exactly per ISO 5807
Oval, diamond, parallelogram, loop hexagon, subroutine symbol — every shape exactly to standard. Strict academic review finds nothing to pick at.
Ten programming languages
Python, JavaScript, TypeScript, C, C++, C#, Java, Go, PHP and Pascal. The engine understands if/else, switch, loops, functions and methods — nesting of any depth.
Built-in visual editor
Right inside rombik: change a block’s text and shape, drag it, draw an arrow. Lasso-select blocks to split the chart into parts or merge them back.
Tall charts split neatly into pages
rombik auto-cuts an oversized chart into A4 pages with connectors (A, B…) — it drops into coursework cleanly, nothing clipped.
rombik right in Telegram
Don’t want to open the site? Send the bot your code in Telegram: a ready flowchart and a .docx land right in the chat.
- As a group: add the bot to your course chat — one shared export balance for everyone, an admin tops up.
- Solo: DM the bot and link your account — render from your own export balance.
- A code file or
/renderwith code → a standard flowchart in seconds.
For the whole group — from $0.38 per export (100-export pack). One admin payment → the whole class renders.
Examples, updates and announcements — our Telegram channel →
Pick format & language → «Generate»
Done! Balance: 41 exports.
What it costs
Building charts is free and needs no account. You pay only when you take the clean file without the watermark.
Exports
from $0.60
per export in a pack. Single export — $0.99. No subscription, no expiry.
Pro
from $2.99
the chart editor for 7 days, 2 exports included.
For a group
from $0.38
per export from a shared chat balance in Telegram: one person pays, the whole group renders.
The on-screen chart and a preview to check your work are always free.
What people say
People who already submitted their charts on time.
to leave a review.
Something broke or have an idea?
Chart came out wrong, or a feature is missing? Drop a line — I read every message and fix things fast.
rombik grew out of my own coursework
The code worked, the assignment didn’t: it still needed a standard-compliant flowchart. Here was the paradox: my lecturer didn’t know Python and spent two minutes working out whether the code was even correct — yet rejected the chart in a second over a single wrong arrow. So instead of drawing dozens of charts by hand, I wrote an engine that does it deterministically, to the standard. The site, the bot and the API are mine too — one developer, not a studio.
Oleksii Odarchuk The full story →
The chart won’t draw itself. rombik will.
Paste your code — the preview is free, no sign-up. In seconds you’ll see a finished standards-compliant chart.
Build a flowchart