TL;DR: Launch(FileURL & "&download=1") often turns a SharePoint file link into a real download instead of a browser preview. It’s a widely used but unofficial SharePoint behavior (only web=1 is officially documented), so test it in your tenant - no flow, no premium connector.

Opening a document from a canvas app with Launch() normally hands the URL to the browser, which happily shows a preview of the PDF, image or Office file. Users then have to hunt for a download button inside the viewer. Appending &download=1 to the SharePoint URL has long been a community trick to make SharePoint serve the file as an attachment, so the browser downloads it straight away. It’s not officially documented - and modern SharePoint doesn’t honor it everywhere - but where it works, it’s a one-liner.

💡 Challenge

You store files in SharePoint and surface their links in a gallery or button. Calling Launch(ThisItem.FileURL) opens the file in the browser’s built-in viewer (preview mode). For a quick look that’s fine, but when users actually need the file on their device, the extra “download from the viewer” step is annoying and, on mobile, sometimes impossible.

✅ Solution

download=1 is a SharePoint URL parameter (not a Power Fx feature) that many makers use to make SharePoint respond with Content-Disposition: attachment, which forces the browser to download the file instead of rendering it. Because Launch() simply appends parameters to the query string, you can add it right in the formula.

⚠️ Reality check: Microsoft only officially documents web=1 (force open in browser). download=1 is an undocumented behavior: it works in many classic file URLs, but modern SharePoint may rewrite or ignore it in some contexts (for example the Quick Links web part). Always test it against your own tenant and file URLs, and keep the Download() alternative below in mind.

🔧 How it’s done

1. Get the file URL from your data source.

🔸 In a SharePoint document library, the file’s absolute URL (FileRef-based) works, for example:

https://contoso.sharepoint.com/sites/Team/Shared Documents/Report.pdf

2. Append the download parameter inside Launch. Use the conventional lowercase download=1.

🔸 If the URL already has a query string (contains ?), add &download=1:

Launch( ThisItem.FileURL & "&download=1" )

🔸 If the raw URL has no ? yet, start the query string with ?download=1 instead:

Launch( ThisItem.FileURL & "?download=1" )

3. Make it robust for both cases so you don’t have to guess:

Launch(
    ThisItem.FileURL &
    If( IsMatch( ThisItem.FileURL, "\?" ), "&", "?" ) &
    "download=1"
)

🔸 This checks whether a ? is already present and picks & or ? automatically.

4. Put it on a button or gallery item OnSelect. Where the parameter is honored, the file downloads immediately on the web; in the mobile player the user is prompted to save it.

🔸 Allow pop-ups if your app is embedded (Teams, SharePoint, Power BI), otherwise the browser may block the new window that Launch() opens.

🎉 Result

Where SharePoint honors the parameter, a single click saves the file to the user’s device instead of opening a preview they then have to download manually. No Power Automate flow, no custom connector, no extra component - just one parameter on the URL.

🌟 Key Advantages

🔸 One-liner: no flow, no premium connector, no component to import.

🔸 Real download (when honored): SharePoint returns the file as an attachment via Content-Disposition, so browsers save instead of preview.

🔸 Works with what you have: any absolute SharePoint file URL already in your gallery or list.

🛠️ FAQ

Q1: Is download=1 an official, guaranteed feature?

No. It’s an undocumented SharePoint URL behavior, not a Power Apps / Launch() feature. Launch() only appends it to the query string; SharePoint decides what to do. The only officially documented sibling parameter is web=1 (force open in the browser). Modern SharePoint may rewrite or ignore download=1 in some contexts, so treat it as a best-effort trick and test it.

Q2: What’s the difference to the native Download() function?

Download(Address) is a documented Power Fx function that downloads a file to the device. In native players (Windows/Android/iOS) the user is prompted for a save location, but in the browser its behavior depends on browser settings - PDFs, images and videos often just open in a new tab. Per Microsoft, Download() also can’t authenticate protected SharePoint links in the mobile player. So Download() is the officially supported route, while &download=1 is an unofficial trick that can force a save more reliably for library files where it’s honored.

Q3: The file still opens in a preview - what’s wrong?

First, remember download=1 isn’t guaranteed. Then check that you appended it with the correct separator (? for the first parameter, & afterwards, lowercase) and that the link is a direct file URL. Some sharing links open a viewer page rather than the file; use the file’s absolute path (FileRef) instead. If it’s simply being ignored by your tenant, fall back to Download(), a document library web part, or a Power Automate flow that streams the file.

Q4: Does the user need permission to the file?

Yes. The download runs in the user’s browser session, so they must have at least read access to the file in SharePoint, just like opening it normally.

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Marcel Lehmann

Marcel Lehmann

Microsoft MVP Microsoft MVP

BizzApps MVP from Switzerland 🇨🇭 - PowerPlatform Expert & Evangelist & MVP - Turning passion into expertise

MVP since 2023 • Power Platform Expert since 2017
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