const myData = { name: "Extension Config", version: 1 }; const blob = new Blob([JSON.stringify(myData, null, 2)], { type: "application/json" }); const url = URL.createObjectURL(blob); browser.downloads.download({ url: url, filename: "config.json" }).then(() => { // Always revoke the URL to free up memory URL.revokeObjectURL(url); }); Use code with caution. Handling Download Progress and Events
browser.downloads.download({ url: "https://example.com", filename: "my-images/saved-image.png", saveAs: false }).then((downloadId) => { console.log(`Download started with ID: ${downloadId}`); }).catch((error) => { console.error(`Download failed: ${error}`); }); Use code with caution. Key Options Parameters The URL of the resource to download.
Browsers often block "automatic" downloads. Ensure your download call is triggered by a user action (like a button click) to avoid being flagged as malicious. javascript browser.downloads.download
The delta object tells you exactly what changed, such as the state moving from in_progress to complete , or the fileSize being updated. Browser Compatibility and Best Practices
Determines what happens if a file with the same name already exists. Options include uniquify (adds a number), overwrite , or prompt . const myData = { name: "Extension Config", version:
Before you can use this method, you must declare the downloads permission in your extension's manifest.json file:
browser.downloads.onChanged.addListener((delta) => { if (delta.state && delta.state.current === "complete") { console.log("Download finished!"); } else if (delta.error) { console.error(`Download failed because: ${delta.error.current}`); } }); Use code with caution. Browsers often block "automatic" downloads
Sometimes you don't have a remote URL; instead, you have data generated locally in your script (like a JSON configuration or a generated CSV). You can still use the downloads API by converting your data into a . javascript
While the browser.* namespace is standard for Firefox and part of the WebExtension polyfill , Chrome uses the chrome.* namespace.
The method accepts an options object and returns a Promise that resolves with the downloadId of the newly created download item. javascript