About Flowcharts
See your code come to life.
Flowcharts are a visual representation of the logic flow through a function or method. They make the structure of code immediately obvious in a way that reading source never quite does — especially for complex branching, looping, and jump logic.
What are flowcharts
A picture is worth a thousand lines.
A flowchart represents the execution path through a function as a diagram of connected nodes. Each node represents a distinct structural element — a terminal node marks where execution starts or ends, a code block node represents sequential statements, a branch node represents a conditional decision, a loop node represents a repeating construct, and a jump node represents a transfer of control such as a return, break, or continue. Together they give you an at-a-glance view of what your code actually does.
Supported languages
Languages DevDiagrams can flowchart.
DevDiagrams uses ANTLR4-generated parsers to parse source code and build flowcharts. Each supported language has a complete grammar that covers the full language syntax.
C#
DevDiagrams supports C# methods and functions including if, switch, for, foreach, while, do, return, break, continue, goto, and throw statements. Paste in one or more method declarations and each one gets its own flowchart.
Java
DevDiagrams supports Java methods including if, switch, for, while, do, return, break, continue, and throw statements. Both regular and generic methods are supported. Paste in one or more method declarations and each one gets its own flowchart.
Python
DevDiagrams supports Python 3 functions including if, elif, else, for, while, return, break, continue, and raise statements. Both regular and async functions are supported, as well as type-annotated functions. Paste in one or more function definitions and each one gets its own flowchart.
Flowchart symbols
Reading a flowchart.
DevDiagrams uses a consistent set of shapes to represent different elements of your code. Each shape corresponds to a specific construct in the source language. Shapes are shown at 1:1 scale using your current preference settings.
Terminal
A rounded rectangle marking the start or end of a function. The start terminal shows the function name. End terminals appear wherever execution leaves the function — including return, throw, and raise statements.
Code Block
A rectangle representing one or more sequential statements that contain no branching or looping logic — assignments, expressions, variable declarations, and similar plain statements.
Branch
A diamond representing a conditional decision — if, elif, or a switch case. The T path exits to the right when the condition is true. The F path exits downward when the condition is false.
Loop
A pair of chamfered rectangles representing a loop construct — for, foreach, while, or do/while. The opening boundary shows the loop condition. The loop body runs between the two boundaries. The closing boundary loops back to the opening boundary.
Switch
A hexagon representing a switch statement. It shows the selector expression and is followed by a series of branch diamonds — one per case. The default case renders on the main spine without a diamond.
B B
Jump nodes
Circles representing transfers of control. A jump source (top) marks where a jump originates and a jump destination (bottom) marks where it lands. Source and destination nodes share the same label so they can be matched visually. Hovering over either highlights both. Labels indicate the jump type:

B — break — exits the enclosing loop or switch.
C — continue — skips to the loop boundary for the next iteration.
g# — goto case / goto default — transfers to a specific case within the enclosing switch statement. The number distinguishes multiple goto case statements within the same switch.
G# — goto label — transfers to a named label anywhere within the same method. The number distinguishes multiple goto statements within the same method.
Features
More than just diagrams.
Source code highlighting
Hover over any node in the flowchart and the corresponding source code is highlighted and scrolled into view in the editor. This makes it easy to trace the relationship between the diagram and the code that produced it.
Jump node linking
Jump nodes — representing break, continue, and return statements — are visually linked to their destination. Hover over any jump node and all related source and destination nodes glow, making it immediately clear where control transfers to.
Export diagrams
Export any flowchart as SVG for crisp vector graphics at any size, or as PNG for embedding in documents and presentations. SVG output can also be copied directly to the clipboard.
Render history
DevDiagrams remembers your previously submitted source files so you can return to them without re-entering your input. History retention is 30 days for free accounts, 6 months for Educational, and 2 years for Professional.
Tips
Writing code that diagrams well.
1
Keep methods focused
Methods that do one thing produce clean, readable flowcharts. A method with many nested conditions and loops produces a wide, complex diagram — which is itself a signal that the method may benefit from being broken into smaller focused methods.
2
Prefer early returns
Methods that use early returns for guard clauses produce flatter, more linear flowcharts than deeply nested if/else chains. The diagram makes the difference immediately visible.
3
Watch for complex switch statements
A switch statement with many cases produces a tall diagram with many branch nodes stacked vertically. If most cases share the same body, consider whether a lookup table or dictionary would be a cleaner design — the flowchart will show this clearly.
4
Use jump node highlighting
Hover over any jump node in the flowchart to see all related source and destination nodes highlighted. This is particularly useful in loops with multiple break and continue statements — the highlighting makes the control flow immediately clear.
5
Paste entire files
You don't have to extract individual methods — paste in an entire class or source file and DevDiagrams will find all the methods automatically. Use the function list panel to navigate between them and the search box to jump directly to any method by name.
Ready to turn your function into a flowchart?
Start flowcharting →