How to download a blob: video URL

Updated 28 October 2026 · 4-minute read

You inspected the page, found the <video> tag, copied its src — and it starts with blob:https://…. You paste it into a new tab: nothing. You feed it to a downloader: nothing. That's not bad luck; it's what blob URLs are designed to do. Here's what's going on and how to actually save the video.

A blob URL is a name tag, not an address

A blob: URL doesn't point to a server. It's a temporary, tab-local reference to data the page is holding in your browser's memory. The page's JavaScript creates it, hands it to the video element, and the browser resolves it internally. Outside that tab — another tab, another app, a downloader — the reference means nothing, and it dies when the tab closes. Copying it is like writing down the coat-check number from a restaurant you've already left.

Why players use blobs

Almost every modern player streams through Media Source Extensions: JavaScript downloads the video in small segments (usually via HLS or DASH), feeds them into a buffer, and the video element plays from that buffer through a blob reference. It's how players adapt quality on the fly — and it means the blob was never a file in the first place. The real, saveable source is the stream the JavaScript is downloading underneath. (Primer: how HLS streaming works.)

So the fix is: ignore the blob, capture the stream

Open devtools → Network while the video plays and you'll see the truth: a playlist (.m3u8 or .mpd) plus a steady drip of segment requests. Those are what a capture tool collects. The manual path is the m3u8 route; the one-click path is an extension that watches the traffic for you.

Vidtuck does this automatically: play the video, click the toolbar icon, and the underlying stream is already in the list with its qualities and duration — the blob never enters the picture. Pick a quality, capture, and the assembled file lands in your Downloads. For the rarer case where the page genuinely built the video in memory as one piece, Vidtuck's detection still catches the underlying media requests that filled it.

What a blob is not

A blob URL is not DRM and not an anti-download trick — it's just plumbing. But the two can coexist: if the stream underneath is Widevine- or FairPlay-protected, no tool can legitimately save it, blob or no blob. Here's how to tell, and why.

And the standing rule: only save videos you have the right to keep — your own content, openly licensed media, or material your access terms let you retain.