Upscale 1080p HD to 4K: Classic, AI & Free Tools Compared

HD and 1080p videos often blur on large screens. How to make HD & 1080p look good on a 4K monitor? You can upscale the HD/1080p video to 4K resolution. Read this article to learn about the relationship between HD, 1080p, and 4K, and the 3 best methods to increase their resolution.

Part 1. Overview: 720p HD vs 1080p FHD vs 4K UHD

What is 720p HD?

HD is short for High Definition. It's also known as 720p, which means it has a horizontal pixel count of 720. The most common dimension is 1280×720 with an aspect ratio of 16:9. With a relatively small file, HD is often used for social media videos to save bandwidth.

What is 1080p FHD?

1080p is also called Full HD (FHD). It's displayed in 1920×1080 resolution and widely used in streaming services like Netflix, gaming, and computer monitors. With 2.25 times the total pixels of an HD display, 1080p delivers more detail and has become a standard resolution for most modern screens.

What is 4K UHD?

4K UHD (Ultra HD) is a high resolution of 3840×2160, approximately 8 million pixels in total. It delivers very sharp images and texture on large screens. It's preferred for high-res TVs and gaming, and some commercial Blu-rays.

720p vs 1080p vs 4K resolution comparison

Why are HD and 1080p blurry on 4K screens?

A 4K screen has 4 times as many pixels as 1080p and roughly 9 times as many as HD, so the monitor has to scale their image to fill the large screen. But it's not smart enough to avoid pixelation. To make HD and 1080p look normal and clear on 4K, use a dedicated video upscaler to enlarge and enhance them

Part 2. Quick Comparison of the 3 Solutions

We tested each tool by upscaling a 720p clip and a 1080p clip to 4K, both at 20 seconds and a 23.98 frame rate. Here's our test environment for reference:

• Processor: Intel(R) Core(TM) i5-10400 CPU @ 2.90GHz 2.90 GHz
• Installed RAM: 16.0 GB (15.8 GB usable)
• Graphics Card: Intel(R) UHD Graphics 630 (128 MB)
• System Type: 64-bit operating system, x64-based processor

Part 3. Batch-Upscale: AVAide Video Converter

Traditional upscaling means that you import the files to a video editor, set a target resolution, and export. The software then calculates new pixels from existing pixels.

AVAide Video Converter is one of the best of its kind. It preserves original quality during the process, and uses optimized hardware acceleration and smart encoding to process lightning fast, even without high-end hardware. It supports video upscaling, converting, and editing in 300+ formats. The best part is that you can upload multiple videos and convert all of them to 4K in one click.

Supported Platforms: Windows/Mac

Processing Time: 16 seconds

Step 1Install the Software

Install AVAide Video Converter for Windows or Mac.

Step 2Upload Video File

Open the software. Click Add Files at the top left corner to upload your video. If you have multiple videos to upscale, you can upload them all.

Step 3Convert to 4K

At the bottom of the window, open the Output Format dropdown menu and select 4K Video. Then click the Convert All button at the bottom right. All the uploaded videos will be upscaled to 4K.

Part 4. AI Upscaler: Topaz Video

Unlike the traditional way, AI upscalers use a trained AI model to predict what missing details should look like. It analyses patterns to reconstruct details that are not clear in the original video.

Topaz Video is among the most powerful AI video upscalers in 2026. While AI upscalers often over-polish videos or invent details, Topaz upscales as naturally as possible. However, it's costly and a bit demanding on hardware, considering the complex AI models it uses. If you're fine with these drawbacks, Topaz is worth a try.

Supported Platforms: Windows/Mac

Processing Time: about 3 minutes

Step 1Import Video File

Open Topaz Video. Drag-and-drop your video file to the interface.

Step 2Set Target Resolution to 4K

On the right-side controls panel, make sure the Enhancement toggle is turned on. Then in the Video OUT menu, select 3840×2160 (4K).

Step 3Choose AI Model

Under Enhancement, choose the AI model named Artemis – Denoise/Sharpen and set the input video condition to High Quality.

Step 4Export Output

Click Export to get the result.

Part 5. Free Online Option: free.upscaler.video

free.upscaler.video is a free resolution upscaler that lets you upscale videos or photos on any browser. It also uses AI technologies to recover details while upscaling the resolution. Compared to the professional Topaz Video, it oversharpens the video more frequently, but for a completely free tool, it's hard to blame.

Supported Platforms: any browser

Processing Time: about 2 minutes

Step 1Upload Video File

Go to free.upscaler.video and click Choose a video or image to upscale. Select the video from your local folders.

Step 2Preview and Upscale to 4K

Select your preferred AI model and check the preview on the left. If you think it looks good, click Start upscaling.

Part 6. FAQs About Upscaling 1080p and HD to 4K

Is 4K better than 1080p?

It depends on your needs. 4K looks much better than 1080p on large screens, while 1080p is more efficient in file size and bandwidth.

Can the human eye tell the difference between 1080p and 4K?

If you sit far away or use a small screen, the difference is mild. But if you sit close, watching on a large monitor, you can tell the difference in pixel density easily – 4K has more pixels per inch, thus looks sharper and clearer.

Can I convert 4K to 1080p?

Yes, you can downscale 4K to 1080p or HD on AVAide Video Converter by setting the output resolution lower.

What's the difference between 1080p and 1080i?

Their resolution is the same: 1920×1080, the main difference being the "p" and "i".

The "p" stands for "progressive scan," which means it draws each line of the video in sequence, producing better visual quality. The "i" refers to "interlaced scan," which paints odd-numbered lines first, then even-numbered, saving bandwidth.

Are 4K and 4K UHD the same thing?

Technically, the 4K resolution refers to a category that includes both 4K UHD (3840×2160) and DCI 4K (4096×2160), so they're not exactly the same. But in everyday use, people often use the 2 terms interchangeably to describe the 3840×2160 resolution.

By Ben Carter on Sep 11, 2026