XML to JSON is a text transform, not a lock
A web app wants JSON and the file you were given is XML.
Tags are turned into JSON in the browser. Attributes and repeated elements may not match the shape your API expects, so read a sample object before you post it.
Do not treat this as security
Broken XML fails. This is encoding of structure, not encryption. Do not use it as a way to hide data.
When XML to JSON is the right page
XML to JSON sits on this site because XML and JSON are not interchangeable, even when they look similar in a file list. A web app wants JSON and the file you were given is XML. Partners who publish an XML schema ask for it even when you exported CSV or JSON. Developers convert JSON when a payload must become a sheet, XML, or CSV.
Tags are turned into JSON in the browser. Attributes and repeated elements may not match the shape your API expects, so read a sample object before you post it.
What you give up by leaving XML
XML is tagged text still used in feeds, invoices, and older integrations. A browser conversion produces a simple dump, not a legal invoice schema with namespaces.
Keep the source. Fixing field names is easier before you send the XML.
What you gain, and do not gain, with JSON
The download has to be JSON, because that is the format the next step named. Developers convert JSON when a payload must become a sheet, XML, or CSV. A list of similar objects maps cleanly to rows.
This is not encryption. Do not paste passwords or live tokens.
A test that matches the real file
Start from the question the other software asked. If it asked for JSON, XML to JSON is the matching page. If it asked for something else, switch tools instead of hoping a similar extension will pass. A web app wants JSON and the file you were given is XML. Tags are turned into JSON in the browser. Attributes and repeated elements may not match the shape your API expects, so read a sample object before you post it. The limit is the part people skip, and it is the part that decides whether the download is usable. Broken XML fails. This is encoding of structure, not encryption. Do not use it as a way to hide data. The text stays in the browser. Try one line you can check before a whole document. Do not paste passwords. Check three things in the download: it opens, the XML material you cared about is still there, and the file size or the layout is what the form described. A new extension alone is not those three things. If a portal, a teacher, or a client rejects the file, send them the original XML as well when you are allowed to. XML to JSON is a convenience copy. It is not a new master. XML to JSON is a text transform for a payload you already understand. Encoding is reversible on purpose. It is not a lock, not a password store, and not a place for production secrets. Check the output before you paste it into a live request, and do not run the tool twice on text that was already encoded.
Here is the decision for XML to JSON. You start with XML and you stop when a real program accepts JSON. Tags can describe nested records better than a flat table. Nested lists of unknown length will not become one tidy sheet. If those two sentences describe a tradeoff you do not want, do not convert. Renaming the extension by hand will not do this job. Running the tool twice on its own output will not do it either.
Broken XML fails. This is encoding of structure, not encryption. Do not use it as a way to hide data.
A related step, if you still need one, is JSON to XML.
Other jobs start from the homepage, where each tool is named for the conversion it actually does.