# URL and DOI links in JabRef

For linking attached files, see [File links in JabRef](https://docs.jabref.org/finding-sorting-and-cleaning-entries/filelinks).

JabRef lets you link documents on the web in the form of an URL or a DOI identifier.

## Setting up external viewers

JabRef has to know which external viewers to use for web pages. These are by default set to values that probably make sense for your operating system, so there's a fair chance you don't have to change these values.

To change the external viewer settings, go to **Options → Preferences → External programs**.

## Opening external links

There are several ways to open an external web page. In the entry editor, click on the icon "open" right of the text field to open the respective DOI or URL.

![Open DOI](https://2944476579-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Lr3JU9j9iSUW8RYz1hD-2910905616%2Fuploads%2Fgit-blob-4c594ba1c468a503109ab1f63f00dda86f3c9a0a%2Fentryeditor-doi-open.png?alt=media\&token=0bb45ffe-6c27-4ec1-98a1-c67da3ecee5b)

In the entry table you can select an entry and use the menu choice, keyboard shortcut or the right-click menu to open the file or web page. Finally, you can click on a URL or DOI icon.

![Open DOI via popup](https://2944476579-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Lr3JU9j9iSUW8RYz1hD-2910905616%2Fuploads%2Fgit-blob-e0ef5e222c2291c83a7e273dc9f54a368ae261d4%2Fentrytable-doi-popup.png?alt=media\&token=a7c75475-755b-43f8-a452-0518c61de073)

By default the entry table will contain a singly column containing an indicator whether there is a DOI or a URL linked. You can remove the "Link identifiers" column in **Options → Preferences → Entry table**.


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.jabref.org/advanced/externalfiles.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.