4K Video Upscaler
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What's new / 2026.09.29

Version 2026.09.29 ·

Your upscaled video is still there after you close the tab

From version 2026.09.29, "View" on the home page reopens your last upscaled video, which this browser keeps for 24 hours, to play it, compare it with the original or download it again. On phones, a video picked from the Android gallery runs from start to finish, an iPhone app's built-in browser saves the result through the share sheet, and an Android app's browser is told to open the page in Chrome first.

Before

A video made in a browser tab usually lives only in that tab: close it before downloading, and it is gone.

Now

Your last upscaled video stays 24 hours in this browser: "View" under "Choose video" plays it, compares it with the original and downloads it again.

Open your last upscaled video again

  1. Find it under "Choose video".

    Come back to the home page in the same browser within 24 hours of the upscale, even after closing the tab or the browser. Under "Choose video" a row shows the video's name, the resolution, format and file size it came out in, and until when it is kept.

    The home page with a row under the drop box: komekami-pv.mp4, Upscaled, 1080p, H.264, 2.9 MB, kept until tomorrow, with a View button and a delete cross
    The last upscaled video, listed under the drop box.
  2. Press "View".

    The video opens where it was made. Play it, drag the line across the picture to compare it with the original, download it again, or change its file size or format with "Export again". If the page no longer has the original, "Choose the original" brings it back for the comparison or a new run; the download works without it.

    The reopened video: the original at 480p on the left and the upscaled 1080p on the right of a gold line; the panel shows Download 2.9 MB, how long it stays in this browser, Choose the original and Export again
    View opens the finished video with its comparison, Download and Export again.
  3. Delete it when you are done.

    The cross at the end of the row deletes it, and asks first if you have not downloaded it yet. Only the newest video is kept: the next one you upscale takes its place.

On a phone: the home page with the upscaled video's row and View under the Choose video button
On a phone, the row sits under Choose video.
On a phone: the reopened video at the top, and under it Download 2.9 MB, how long it is kept, and Choose the original
View puts Download right under the video.

Pick a video straight from the Android gallery

Press "Choose video" on an Android phone or tablet and pick the video in the gallery that opens. The page opens it and upscales it from start to finish. Some phones stop letting the browser read a gallery video after a while; if that happens when you press Start, the panel says so and offers another way in.

  1. Press "Choose it from Files".

    The panel says "Your phone's gallery stopped letting the browser read this video", and its gold button becomes "Choose it from Files". Files opens the file itself rather than the gallery's view of it.

    An Android tablet: the workbench with the clip, and the panel under Start saying the phone's gallery stopped letting the browser read this video, with the gold button Choose it from Files
    On an Android tablet: the words and the button under Start.
  2. Pick the same video and press Start again.

    Files has a Videos filter at the top. For the rest of the visit, "Replace" and the home page open Files too.

An Android phone: the panel under Start saying the phone's gallery stopped letting the browser read this video, and the gold button Choose it from Files
The same on a phone.

Save the video in an app's built-in browser

Apps like the Google app, Facebook, Instagram and TikTok open links in a browser of their own. What you do there to keep the finished video depends on the phone:

Where the page is openWhat the page showsWhat to do
Safari, Chrome, Samsung Internet"Download" when the video is doneTap Download, as with any file.
An app on an iPhone or iPad (the Google app, say)"Save video" when the video is doneTap Save video. In the menu that opens, tap Save Video to put it in Photos (tap Allow if asked), or Save to Files.
An app on an iPhone whose browser cannot share filesA card at the top: "Open this page in Safari first."Tap the app's three dots (••• or ⋯) or its share icon, choose "Open in Safari" or "Open in browser", and choose the video again there.
An app on Android (Facebook, TikTok, the Google app …)A card at the top: "Open this page in Chrome first."Tap the three dots (⋮ or ⋯) at the app's top right, choose "Open in Chrome" or "Open in browser", and choose the video there. Chrome saves it to Downloads.
The Google app's browser on an iPhone: the finished video's panel with the gold Save video button and the line under it on Save Video and Save to Files
In an iPhone app: Save video, and where it goes.
The share sheet over the page: komekami-pv-1080p, Video, 3.1 MB, with Save Video, Add to Shared Album and Save to Files
The menu that opens: Save Video or Save to Files.
Facebook's browser on an Android phone: a card above the title, Open this page in Chrome first, with where to find Open in Chrome
In an Android app: the card before you choose a video.

When the browser switches WebGPU off

If the graphics chip stops responding twice within 2 minutes, Chrome and Edge switch WebGPU off in every tab, and say nothing. The panel now tells you which case you are in, and Start stays off until WebGPU answers again:

WhereWhat the panel saysWhat to do
A computerIt can come back by itself within about two minutes, and Start turns back on when it doesWait. If it is still off after that, quit the browser completely (every window) and open it again
A computer, laterThe browser keeps WebGPU off until it restartsQuit the browser completely (every window, not just the tab) and open it again
A phoneIt comes back by itself within about two minutesWait, or swipe the browser away from recent apps and open it again to have it back at once
The workbench on a computer with WebGPU switched off: Start greyed out, and under it the panel's words that the graphics chip stopped responding, that WebGPU can come back by itself within about two minutes and what to do if it stays off
On a computer, a moment after WebGPU went off: Start waits.
The panel once WebGPU answers again: the gold Start button, its estimate, and the line WebGPU is back on. Start works again.

The page asks the browser again every 10 seconds while it is on screen. When WebGPU answers, Start turns back on by itself and the panel says "WebGPU is back on. Start works again." A job that stopped keeps its saved progress, and Start picks up from there.

An Android phone with WebGPU switched off: Start greyed out and the panel's words that it comes back by itself within about two minutes, or at once after swiping the browser away
On a phone, the panel's own words.

How your browser keeps and reopens the video

From version 2026.09.29, 4K Video Upscaler keeps what it needs in your browser's private storage for this site: the finished video, a short note about it, and on Android a copy of the video you picked. Nothing is uploaded. The upscaling runs on your own graphics chip through WebGPU, and the page watches for WebGPU to come back when the browser switches it off.

Copied as it arrives

256 MiBthe largest video an Android pick is copied up to

A gallery video the phone cannot take back

On Android, the moment you pick a video the page copies it into its own storage in the browser, as it arrives. The run reads that copy, so it does not matter if the gallery stops sharing the file later, and View can compare with it afterwards. A bigger video is kept open instead until you close the page.

The copy never leaves the phone and is deleted with the job or the kept video.

Kept in the browser

24 hthe last upscaled video stays in this browser

Reopened from a short note beside the video

The finished video is written to the browser's private storage while it runs. Beside it the page keeps a short note: the settings, the size, the original's frame and length. The home page reads the note to list the video, and View rebuilds the finished view from it, with the original the page still has: the Android copy, or the frames a trimmed run used.

Only the newest video is kept; clearing this site's data in the browser deletes it too.

WebGPU watch

10 sbetween two checks while WebGPU is off

Start turns back on by itself

Chrome switches WebGPU off in every tab once its graphics chip stops responding twice within 2 minutes, and nothing on screen says so. The page remembers when it last saw the chip stop, in this browser only, so a missing graphics adapter within the next 60 minutes reads as that switch, not as a driver to update. While WebGPU is off it asks again every 10 seconds, only while the page is on screen.

The time itself never leaves this browser.

Questions about this version

Where do I find a video I upscaled earlier?
On the home page, in the same browser, within 24 hours of the upscale: under "Choose video" there is a row with its name and until when it is kept. Press View to open it. Only the newest video is kept.
Can I still compare the reopened video with the original?
Yes, when the page still has the original: a video picked on Android, or the part a trimmed run used. Otherwise press "Choose the original" and pick the same file; the download works without it.
My Android phone says to choose the video from Files. What happened?
The phone's gallery stopped letting the browser read the video. Press "Choose it from Files" and pick the same video; Files opens the file itself, and Start works again.
How do I save the video inside the Google app on an iPhone?
When the video is done, tap "Save video". In the menu that opens, tap Save Video to put it in Photos (tap Allow the first time), or Save to Files.
Why does the page ask for Chrome inside Facebook or TikTok on Android?
An Android app's built-in browser cannot save a video made in the page. Open the page in Chrome from the app's three dots (⋮ or ⋯) at the top right, then choose the video there; Chrome saves it to Downloads.
The panel says the browser switched WebGPU off. What now?
The browser does that after the graphics chip stops responding twice within 2 minutes. On a computer it usually comes back by itself within about 2 minutes, and Start turns back on; if it stays off, quit the browser completely and open it again. On a phone, wait, or swipe the browser away and open it again.

Try itHow to use it

Footage: Komekami! Girl's PV (2026), official channel, CC BY 4.0 via Wikimedia Commons, re-encoded at 220 kbit/s. Screenshots: the page on 29 September 2026; phones and app browsers are Chrome showing the page as that browser gets it, the share sheet is the iOS 18 simulator.