![]() ![]() If you want to automate this task for your website screenshots, let Stillio do the heavy lifting. You even get the niceties of overcoming the dreaded CORS error. To prevent memory leaks we have to revoke the URL with the URL.revokeObjectURL function when we no longer need the image. If you're already calling a Node.js back-end to feed your front-end, why not add an endpoint to help you download remote images with a better experience. Using the web URL.createObjectURL API we can turn a file object into a URL and offer it as a download to the client. ![]() If you're working with large images, consider a static solution. AWS limits the size of request bodies to ~6MB. If you're using a serverless solution, be mindful of their Request Payload size limits. This simply takes the data in the result body and feeds it into the body of the response to the client. image/png for the content-type header and file extension to be accurate. ![]() Note here too you might want to have some sort of library or checker to determine the image MIME type e.g. Setting the appropriate headers for the response:Ĭontent-dispostion with a value of attachment will tell the browser to save the file instead of the alternative inline which will try to render the response in the browser.Instead of making a fetch directly to the image, you will make it to your Node.js API endpoint, which could be set up as follows: The following example only requires one simple change to the download logic on the client - the URL. a Node.js server - CORS can be safely bypassed. Luckily, for requests not coming from a browser e.g. Making image download robust with Node.js CORS or Cross-Origin Resource Sharing may many times cause the download to fail from the browser if the resource is not on the same origin, or doesn't have the appropriate headers set. This experience may be more user-friendly, but don't be surprised if you run into the notorious CORS wall. Because the anchor tag has an object URL, the browser will initiate the download to the user's Download Folder. ![]() The client-side code above listens to a click on the HTML button, fetches the image as a blob, creates an objectURL, adds it to a newly created (hidden) anchor tag and clicks it to initiate a download. This tells the browser to request cross-origin access when downloading the image data. Enter fullscreen mode Exit fullscreen mode The key is to use the crossorigin attribute by setting crossOrigin on the HTMLImageElement into which the image will be loaded. ![]()
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