What is a .xsn file?
You’ve found files with the .xsn extension in an old SharePoint library or a network share, nothing on the machine opens them, and the software that made them is being retired. Before you can rescue what’s inside, it helps to know what the file actually is — because it isn’t a document.
A .xsn file is a Microsoft InfoPath form template: a cabinet (.cab) archive containing the form’s XSLT layout stylesheets, XML schema, and manifest — but none of the data people typed into the form. The submitted data lives in separate .xml record files, one per filled-in form.
Below: what’s inside the cabinet, why it’s still readable in 2026, and the related file types you’ll find next to it.
What’s inside a .xsn file
Rename a .xsn to .cab and any cabinet extractor will open it — that’s literally all the extension hides. Microsoft publishes the full template format as the MS-IPFF specification, and the layout stayed stable from InfoPath 2003 through 2013, the final version — so a template designed twenty years ago and one from last year unpack the same way. Inside, a handful of files do all the work:
| File | Role |
|---|---|
manifest.xsf | The form definition: names the views, data sources, rules, and every other file in the cabinet |
view1.xsl … | XSLT stylesheets — each “view” of the form is one of these, and they still render today in any XSLT processor |
myschema.xsd | The XML schema submissions had to follow |
template.xml, sampledata.xml | A blank record and designer sample values |
images, script.js, .dll | Form graphics and optional code-behind |
Why .xsn files are still readable after InfoPath
InfoPath kept the template separate from the data: every submitted form is a standalone .xml file that references the template. Both halves are open, documented formats — plain XML and XSLT inside a standard cabinet — so nothing about reading them depends on InfoPath existing. That’s why, even with InfoPath and Forms Services retired, the files remain fully readable: the view stylesheets are ordinary XSLT that any modern XSLT processor, including the one in your browser, can still run.
The openxsn tool is built on exactly that: it unpacks the cabinet and renders your records through the form’s own view stylesheets, in your browser; from there they export to searchable PDF or Excel. What’s gone with the retirement is the editing and hosting machinery — the designer, the browser forms service in SharePoint — not the ability to read what those tools produced.
InfoPath file types you’ll find alongside a .xsn
| Extension | What it is |
|---|---|
.xml | A submitted record — one per filled-in form; the half that holds your data |
.xsf | The form definition file — the same manifest.xsf that lives inside the cabinet, sometimes found extracted |
.xtp2 | A template part — a reusable fragment designers shared between forms |
.udcx | A data-connection file pointing a form at a SharePoint list or web service |
For rescue purposes only the first row matters: gather the .xml records with their .xsn template and you have everything needed to open and render the archive.
Curious what’s in yours? Drop it in — the parse and first previews are free, and the file never leaves your machine.
Look inside your .xsnQuestions
Is a .xsn file dangerous to open?
The archive itself is just XML and stylesheets, but templates could also carry code-behind (.dll files) that ran inside InfoPath. Tools that merely read the cabinet — like this one — never execute anything; the code files are simply ignored.
Why is my data not in the .xsn?
By design. InfoPath separated the form (template, one .xsn) from the submissions (data, one .xml per filled-in form). It’s why a form library holds one template and thousands of records — and why you need both halves for a faithful rendering.
What program opens .xsn files in 2026?
With InfoPath retired and no official viewer, the practical options are a browser-based reader like the openxsn tool (renders the form and its records) or a cabinet extractor for raw access to the files inside — both covered step-by-step in how to open a .xsn file.
Can I edit a .xsn file?
Technically yes — extract, edit, repack with makecab — but with InfoPath retired, almost nothing remains that consumes an edited template (only on-premises SharePoint Server still runs Forms Services). In 2026 the practical operations are reading it, rendering records through it, and archiving it.