Your video stays with you
For the level you pick, the tool downloads the AI model: under 0.4 MB, or about 10 MB for Ultra on first use (model plus runtime files). Your video is never uploaded to our servers.
Upscale Video to 4K Free Online
Free, in your browser: by default, the AI doubles your video's width and height, so on a computer or Android, 1080p becomes 4K (3840×2160) and 720p becomes 2K (2560×1440). Your video never leaves your device.
- No upload
- No signup
- No watermark
- No daily limit
A free AI video upscaler that runs on your own device
It decodes, upscales and re-encodes every frame of your video on your own device, using your GPU.
No daily limit, no watermark
Upscale as many videos as you like. Downloads carry no watermark and use no credits.
Speed depends on your GPU
Your own graphics hardware does the work, so a stronger GPU finishes sooner.
Convert Video to 4K: Before and After
BeforeAfterAI videoIllustrative
BeforeAfterReal videoIllustrative
1080p to 4K, 720p to 2K: what resolution will your video reach?
The free upscaler doesn't upscale to a fixed target size. By default, it doubles your video's width and height, within your device's limit (you can also pick a smaller output size), so two things decide what you get: the resolution of your video and the device you're using.
1080p (1920×1080)
- On a computer or Android
- 3840×2160 (4K)
- On iPhone or iPad
- Stays at 1920×1080 (no upscale)
720p (1280×720)
- On a computer or Android
- 2560×1440 (2K)
- On iPhone or iPad
- Up to 1920 px on the long edge
480p
- On a computer or Android
- 960p
- On iPhone or iPad
- 960p
Need 4K from 720p, or 4K on an iPhone or iPad? That's what Pro is for. From 480p, Pro's Topaz model goes up to 4×, about 1920p, not 4K (2160p). See Free vs. Pro below.
The rules behind every upscale
These rules are the same for every video, so you can predict the result before you press start.
2×
- What it means
- By default, every model doubles width and height, within the device limit; you can also pick a smaller output size. Fast, Balanced, Quality and Ultra offer the same output sizes.
3,840 / 1,920 px
- What it means
- The longest-edge limit: 3,840 px on computers and Android, 1,920 px on iPhone and iPad.
MP4
- What it means
- The tool tries H.264 first and saves an MP4 or WebM, depending on your browser, the video codec and the original audio. If the original audio can't be kept, the job is refused before it starts.
No fixed length limit
- What it means
- Longer videos take longer, and finishing depends on your device's memory and free storage. Output files over about 1.9 GB need direct saving to disk, available in desktop Chrome and Edge. The job runs inside the page, so it stops if you close the tab; in desktop Chrome or Edge you can resume an interrupted large job.
SDR only
- What it means
- HDR video isn't supported, and your browser has to be able to play the file.
Choose a model and a browser
All four models give the same output size. What changes is the size of the AI model: Fast, Balanced and Quality are the same kind of model at three sizes, and Ultra is a larger, slower model that runs only on a computer with WebGPU. Quality also needs WebGPU.
Fast
- Download
- Under 0.4 MB
- Where it runs
- Computers, Android (Chrome), iPhone and iPad (Safari)
Balanced
- Download
- Under 0.4 MB
- Where it runs
- Computers
Quality
- Download
- Under 0.4 MB
- Where it runs
- Computers with WebGPU
Ultra
- Download
- About 10 MB on first use (model plus runtime files)
- Where it runs
- Computers with WebGPU
How to choose: check the preview first. On a computer, before the full run, the tool shows a few of your own frames before and after, so you can see whether a slower model is worth the extra time.
Chrome, Edge, Opera (computer)
- Support
- Recommended. For output files over about 1.9 GB, use Chrome or Edge.
Safari (Mac)
- Support
- Supported.
Firefox
- Support
- Supported with WebGPU, which is enabled by default in some Firefox versions and systems.
Chrome (Android)
- Support
- Fast model only.
Safari (iPhone, iPad)
- Support
- Fast model only.
What 4K upscaling can and can't fix
What it does
- Gives every frame more pixels, so your video fills a larger screen.
- Uses an AI model to predict the new pixels, instead of stretching the ones you have like a plain resize.
- Keeps your original audio.
What it can't do
- Guarantee detail that was never recorded. The AI predicts new pixels from your video, so it can't guarantee that a face that's a blur in the original comes out sharp.
- Match footage filmed in 4K. The file is a real 3840×2160 video, but the new pixels are predicted, not recorded.
How to get the best result
Find your situation in the left column.
You have the same clip at different resolutions
- What to do
- Use the highest-resolution copy
- Why
- By default, the output is 2× the input. The 1080p original becomes 4K; a 720p copy of the same clip only reaches 2K.
You're on an iPhone or iPad
- What to do
- For 4K, use a computer or Pro
- Why
- The free tool can't reach 4K on iPhone or iPad.
Your file won't open
- What to do
- Try Pro: it converts MP4, MOV, MKV, AVI, WebM, TS, MTS, M2TS, WMV, MPG and more in the cloud, including files your browser can't decode (up to 1 GB and 10 minutes)
- Why
- A supported extension isn't enough. An .mkv or .mov file can hold a codec your browser can't decode.
Your video was recorded in HDR
- What to do
- Use an SDR copy
- Why
- HDR isn't supported, and recent iPhones record video in HDR by default.
Your video is long and you can't keep the page open
- What to do
- Use Pro (videos up to 10 minutes)
- Why
- Pro runs in the cloud, so you can close the page and download later.
How to upscale video to 4K free
Choose your video
MP4, MOV, MKV and other common formats, as long as your browser can play the file.
Pick a model and check the preview
On a computer, the preview shows a few of your own frames before and after.
Download
Every frame is upscaled in your browser. Save the finished video when it's ready.
Upscale to 4K: Free vs. Pro
Price
- Free (this page)
- Free, no credits
- Pro
- Credit packs from $9.90
Output
- Free (this page)
- 2× your video, up to 3840 px on the long edge
- Pro
- Up to 4K (3840×2160)
4K from 720p or 480p
- Free (this page)
- No: 720p to 2K, 480p to 960p
- Pro
- 720p: yes, pick 4K. 480p: Topaz goes up to 4×, about 1920p, not 4K
Where it runs
- Free (this page)
- Your own device. Video not uploaded; tab stays open
- Pro
- In the cloud. Close the page and download later
Video length
- Free (this page)
- No fixed limit
- Pro
- Up to 10 minutes
Phones and tablets
- Free (this page)
- Fast model; up to 1920 px on iPhone and iPad
- Pro
- Same output on every device
Pro makes more sense when you need 4K from a 720p video, want 4K on an iPhone or iPad, or don't want to keep a tab open while the video processes.
FAQ
Free video upscaler: questions
01
Is it really free, with no sign-up and no watermark?
Yes. No sign-up, no login, no card, no watermark, no credits and no daily limit. Credits are only used by Pro, the cloud version.
02
Is this a local AI video upscaler? Does my video get uploaded?
It's local, and nothing is uploaded. Decoding, AI upscaling and encoding all run inside your browser on your own device, so there's no software to install. Apart from the page itself, it downloads only what the tool needs to run, such as the AI model.
03
How do I upscale 1080p to 4K for free?
Open this page on a computer or an Android phone, drop in your 1080p video, pick a model and download. A 1920×1080 video comes out at 3840×2160. On iPhone and iPad the free tool can't reach 4K.
04
Can I upscale 720p to 4K?
Not with the free tool. By default it doubles, so on a computer or Android, 720p becomes 2560×1440 (2K). Pro can output 4K from 720p. From 480p, Pro's Topaz model goes up to 4×, about 1920p, not 4K.
05
Can I convert a regular video to 4K?
With the free tool on a computer or Android, the default output reaches 4K from 1080p or higher; 720p becomes 2K and 480p becomes 960p. Instead of stretching the pixels you have, like a plain converter, it uses an AI model to predict the new ones, then saves the result as an MP4 or WebM. For 4K from 720p, use Pro.
06
Does upscaling to 4K really work? Is it the same as real 4K?
You get a real 3840×2160 file, but it isn't the same as footage filmed in 4K: the new pixels are predicted, not recorded, so detail that was never captured can't be guaranteed to come back. It's worth it for a 4K screen, or when you need a 4K file to edit or upload.
07
How is this different from other free video upscalers?
It runs entirely on your own device: nothing is uploaded, and there's no sign-up, watermark or daily limit. The trade-offs: speed depends on your GPU, and with the default output, the free tool reaches 4K from 1080p or higher on a computer or Android.
08
Can I upscale a long video or a full movie?
There's no fixed length limit, but longer videos take longer, and finishing depends on your device's memory and free storage. Output files over about 1.9 GB need direct saving to disk, available in desktop Chrome and Edge. The job runs inside the page, so keep the tab open until the download is ready; in desktop Chrome or Edge you can resume an interrupted large job. If you'd rather close the page, Pro processes videos up to 10 minutes in the cloud.
09
Can I upscale old videos to 4K?
With the free tool on a computer or Android, the default output reaches 4K from 1080p or higher. Digitized tapes are usually standard definition, around 480p, which the free tool turns into 960p; in Pro, Topaz goes up to 4×, about 1920p, not 4K. Either way, expect a larger copy of what's there, not a restored original.
10
Does it work on iPhone or Android?
Yes, with the Fast model: Chrome on Android and Safari on iPhone and iPad. Android can reach 3840 px on the long edge; iPhone and iPad stop at 1920 px, so a 1080p video isn't upscaled there.
11
How long does it take, and what computer do I need?
Use a desktop or laptop; the AI runs on your GPU. With WebGPU (for example in Chrome or Edge) you get all four models; without it, a slower compatibility mode offers Fast and Balanced. Time depends on your GPU, the model you pick, and the length and resolution of your video.
12
Which model should I choose, and why can't I see all four?
Fast, Balanced and Quality are the same kind of model at three sizes. Ultra is larger and slower and needs a computer with WebGPU, and phones and tablets offer only Fast. To see all four, use Chrome or Edge with WebGPU on a computer, then compare them on the preview frames of your own video.
13
Which formats work, and what file do I get?
You can open MP4, MOV, AVI, MKV, WebM, TS, MTS and M2TS files, as long as your browser can play the video inside. HDR video isn't supported. The tool tries H.264 first and saves an MP4 or WebM, depending on your browser, the video codec and the original audio; if the original audio can't be kept, the job is refused before it starts.
Still unsure?Contact support →
Upscale your video to 4K free
Drop a video into the tool above and download it at up to twice the resolution. Nothing to install, and your video is never uploaded.
Maintained by AIUpscaler.video · Questions or problems: support@aiupscaler.video