Free BPMN Validator
Upload a .bpmn file and check it against 19 normative rules from the OMG BPMN 2.0.2 specification, with the exact spec clause cited for every failure. Free, no account, and your file never leaves the browser.
What the validator checks
Referential integrity
Every sequence flow, message flow, and lane reference points at an element that actually exists.
Start and end events
Start events have no incoming flows, end events have no outgoing flows, and every process that has one has both (§10.5.2 and §10.5.3).
Gateway structure
Gateways either split or merge, never both at once; event-based gateways target only the element types the spec allows (§10.6).
Pool boundaries
Sequence flows stay inside one pool; message flows always cross pools and connect valid endpoints (§8.4.13, §9.4).
Token flow
Every node sits on a path from a start event to an end event, so no token can get stranded.
Conditions and defaults
Diverging exclusive gateways label their branches or declare a default flow; parallel gateways and start events carry no conditions (§10.6.2 and §10.6.3).
Naming conventions
Unnamed activities and decision gateways not phrased as questions are flagged as warnings, not errors.
Frequently asked questions
Is my BPMN file uploaded to a server?
No. The validator runs entirely in your browser using the bpmn-js engine. Your file never leaves your device, which also means it works offline once the page has loaded. If you choose to email yourself the report, only the pass/fail summary and rule notes are sent, never the file.
What rules does the validator check?
It checks 19 rules derived from the OMG BPMN 2.0.2 specification (formal/2013-12-09): referential integrity, start and end event constraints, gateway fan rules, pool and message-flow boundaries, token-flow reachability, branch conditions and default flows, and naming conventions. Every failure cites the exact clause and page of the spec.
Why does my file open fine in my modeler but fail here?
Most modeling tools only check that the XML is well-formed, not that the process follows the normative rules of the spec. A diagram can render perfectly and still violate token-flow or gateway rules that break execution engines and confuse readers.
What file types are supported?
Any BPMN 2.0 interchange file: .bpmn or .xml exported from Camunda Modeler, bpmn.io, Signavio, Bizagi, Visio (with BPMN export), Lucidchart, and most other BPMN tools.
Can it fix the problems it finds?
The validator reports issues; it does not rewrite your file. If you want a diagram that is generated valid in the first place, Swimdraft creates BPMN from notes or transcripts and automatically repairs it until it passes every check.
Tired of fixing invalid diagrams?
Swimdraft generates BPMN 2.0 diagrams from your notes and transcripts, then auto-repairs them until they pass every one of these checks. First 5 diagrams free.
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