.uri File Extension

What kind of file is a .uri?

A .uri file is normally a plain-text list of Uniform Resource Identifiers. Its registered text/uri-list MIME type permits URLs, URNs, and identifiers that use other URI schemes. IANA recommends both .uri and .uris as filename extensions for this format.¹

The syntax is deliberately small. Each non-comment line contains one complete URI, lines beginning with # are comments, and the registered format uses CRLF line endings. There is no magic number. A text file containing web addresses could instead be ordinary text or application-specific data, so the declared MIME type and file contents are more reliable than the suffix alone.

How do I open a .uri on my computer?

Open a trusted .uri file in a text editor such as Notepad on Windows, TextEdit on macOS, or a desktop editor on Linux. Browsers use text/uri-list internally for operations such as dragging links, but they do not necessarily provide a dedicated viewer for a downloaded .uri file.²

To visit an entry, copy a known HTTP or HTTPS URL into a browser. Inspect the scheme and destination before opening anything unfamiliar. A list can contain file:, mailto:, custom application schemes, or references that trigger downloads and network requests.

Poly support for .uri

Poly stores, syncs, shares, versions, and finds standalone .uri files by name. It does not currently infer text/uri-list from the .uri suffix or treat a multi-entry file as a collection of bookmarks, so the file has no in-app content preview, content indexing, or agent reading.

For links you want to search and open in Poly, create a bookmark for each destination. Poly bookmarks represent one destination apiece and can use available page metadata and supported page content. This is distinct from an RFC 2483 file, which may contain several URI lines and comments.

History of .uri

The IETF URN Working Group designed text/uri-list for automatic processing of lists of resource identifiers. RFC 2483, published in January 1999 as an Experimental RFC, registered the media type and recommended .uri or .uris as its extensions.³

Its original setting was URI resolution. A service could return alternate names or locations for a resource, with an optional first-line comment recording the original URI. The compact representation later found a durable role in web drag-and-drop data, where browsers can carry a URI-list value alongside a plain-text fallback.²

Working with .uri and alternatives

Choose a format based on how the destinations will be used:

Preserve the original URI strings unless normalization is intentional. Query strings, fragments, percent-encoding, and parts whose case matters can change the destination. Treat every entry as untrusted instructions: validate its syntax, allow only expected schemes, and avoid automatically fetching an entire unknown list. The registration specifically warns that URI lists can expose confidential locations and attract traffic analysis.¹