How to open a JSON file online
Three steps, a few seconds, no software.
Open your .UML file
Drop it on the box, choose it from your device, or paste the data straight in.
View the structure
Your .UML file opens as a tidy, foldable tree, with the exact line of any error pointed out.
Search, copy or download
Search keys and values, copy any path or value, switch to a table, or download a clean copy.
What is a .UML file?
The most common data format on the web.
A UML file contains a Unified Modeling Language diagram or model, most commonly created by Visual Paradigm or the Eclipse UML2 plugin. Open it in the application that created it; Visual Paradigm Community Edition is free. There is no universal UML viewer; the format is XML-based but tool-specific.
Programs that open .UML files
| Full name | UML Diagram / Model File |
|---|---|
| Developer | No single owner — the .uml extension is used by multiple UML tools, primarily Visual Paradigm |
| First released | UML standard: 1997 (OMG); .uml extension: tool-dependent (mid-2000s onward) |
| Category | Text & Code |
| MIME type | application/xml |
Related viewers
Every viewer is free to use.
Frequently asked questions
Is my .UML file uploaded anywhere?
No. The file is opened directly from the copy you pick.
My .UML file is invalid. Can you fix it?
We show the exact line and column of the first error. For common problems like comments, trailing commas, single quotes or Python-style True/False/None, click Try to repair and download the fixed file.
How large can the file be?
Up to 50 MB. The tree only builds the branches you open, so even multi-megabyte files stay responsive.
What is JSONPath?
A path like $.orders[3].customer.email that points to one value inside the data. Click any node to see its path and copy it for code, jq or your API docs.
Can I see my data as a table?
Yes. Any array of objects can be shown in the Table view and downloaded as CSV.
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