Fetch data


  • Like browsers, Deno implements web standard APIs such as fetch .
  • Deno is secure by default, meaning explicit permission must be granted to access the network.
  • See also: Deno's permissions model.


When building any sort of web application developers will usually need to retrieve data from somewhere else on the web. This works no differently in Deno than in any other JavaScript application, just call the fetch() method. For more information on fetch read the MDN documentation .

The exception with Deno occurs when running a script which makes a call over the web. Deno is secure by default which means access to IO (Input / Output) is prohibited. To make a call over the web Deno must be explicitly told it is ok to do so. This is achieved by adding the --allow-net flag to the deno run command.


Command: deno run --allow-net fetch.ts

 * Output: JSON Data
const jsonResponse = await fetch("https://api.github.com/users/denoland");
const jsonData = await jsonResponse.json();

 * Output: HTML Data
const textResponse = await fetch("https://deno.land/");
const textData = await textResponse.text();

 * Output: Error Message
try {
  await fetch("https://does.not.exist/");
} catch (error) {