> ## Documentation Index
> Fetch the complete documentation index at: https://www.canva.dev/docs/button/llms.txt
> Use this file to discover all available pages before exploring further.
# Downloading designs
Download a published design with the JavaScript API.
The Canva editor has a **Publish** button. When a user clicks this button and navigates through the publishing workflow, your website can use the JavaScript API to download the user's design as an image file.
To detect when a user publishes a design, register the [`onDesignPublish`](https://www.canva.dev/docs/button/javascript/api-reference/on-design-publish/) callback via the [`createDesign`](https://www.canva.dev/docs/button/javascript/api-reference/create-design/) or [`editDesign`](https://www.canva.dev/docs/button/html/downloading-designs/) methods:
```javascript
api.createDesign({
design: {
type: "Poster",
},
onDesignPublish: (opts) => {
console.log(opts.exportUrl);
},
});
```
The `onDesignPublish` callback receives an `opts.exportUrl` argument. This argument contains the URL of the user's published design. You can use this URL to download the design.
You can control the export format of the user's design by setting the `opts.editor.fileType` argument in the `createDesign` method:
```javascript
api.createDesign({
design: {
type: "Poster",
},
editor: {
fileType: "jpg",
},
onDesignPublish: (opts) => {
console.log(opts.exportUrl);
},
});
```
The default value is `png`.
**Tip:**
The URL of the user's design expires after 15 minutes.
## Example
```markup
Canva Button
```