What is MIME type "application/n-quads"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

The MIME type application/n-quads signals that a file contains data in the N-Quads format.
It is a plain text serialization for RDF data. Each line holds four parts: subject, predicate, object, and a graph identifier. This extra part extends the N-Triples model by adding context to each statement.

Semantic web data exchange: It allows complex datasets to be shared.
Linked data publication: It helps in publishing structured data for discovery.
Graph storage: It separates data into different graphs for advanced queries.

Files using this format carry the extension NQ.
The MIME type ensures applications know how to parse and display the content.
For more detailed specifications, visit the W3C N-Quads Recommendation.

Associated file extensions

.nq

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: application/n-quads

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="application/n-quads">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');    
    
    http.createServer((req, res) => {    
      res.setHeader('Content-Type', 'application/n-quads');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.nq

FAQs

What is the application/n-quads MIME type used for?

This MIME type identifies files containing RDF datasets formatted as N-Quads. Unlike standard triples, N-Quads include a fourth element—the graph label—which allows multiple named graphs to be stored and exchanged in a single text file. It is widely used for dumping data from quad-stores.

How can I open a file with the .nq extension?

Since N-Quads are a line-based plain text format, you can open them with any standard text editor like Notepad, VS Code, or Sublime Text. For analyzing the semantic relationships within the data, you should use RDF-aware tools or graph databases such as Apache Jena, RDF4J, or Virtuoso.

What is the difference between application/n-quads and application/n-triples?

The primary difference is the scope of the data. While application/n-triples stores statements as Subject-Predicate-Object, application/n-quads adds a fourth component: the Context (or Graph Name). This makes .nq files capable of representing multiple distinct graphs, whereas .nt files represent a single graph.

How do I configure Apache to serve .nq files?

To ensure your Apache server sends the correct Content-Type header, add the following line to your .htaccess file or main configuration: AddType application/n-quads .nq. This prevents the file from being served as generic text/plain.

How do I configure Nginx for N-Quads support?

You should update your mime.types file or the types block in your Nginx configuration. Add the line application/n-quads nq; to map the extension to the correct MIME type. Reload Nginx to apply the changes.

Why does my browser download .nq files instead of displaying them?

Most web browsers do not have native rendering engines for RDF or Linked Data. Even with the correct MIME type, the browser defaults to downloading the file because it doesn't know how to visualize the graph structure. You may need a specific browser extension or a web-based RDF visualizer.

Is application/n-quads compatible with JSON-LD?

Both are RDF serialization formats, but they serve different purposes. application/n-quads is a simple, line-based format ideal for streaming and bulk data transfer. In contrast, application/ld+json is a hierarchical JSON format designed for web APIs and easier consumption by frontend JavaScript applications.

Should I use text/x-nquads or application/n-quads?

You should use application/n-quads. This is the standard media type registered with the IANA and recommended by the W3C. The text/x-nquads type is an experimental or legacy identifier and may not be recognized by modern parsers.

General FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.