In your opinion, what are the best free image upscalers, and why?

Upscaling can never be good enough compared to a high-resolution image.

A digital image is created with numbers - also called pixels - and these numbers are assigned once the image is shot.

How it works:

The upscaling app increases the number of pixels and fills these pixels with the nearest real pixel's image information. For example, if the area is pink, the app will add more pink pixels. However, this does not always work as smoothly as it sounds. The resulting image is often blurry or does not give the required results.

AI-powered upscaling apps are the best so far. Even if some apps are not AI-powered, they claim that they are. So the investigation on this subject needs to be deeper...

AI-powered upscaling apps not only check the nearest pixels (after increasing their number) but also compare the image with their image database. For example, the AI understands that the filled area is skin, so it not only fills the area with skin colour but also gives skin texture.  If the area is hair, it fills the area with hair texture. This makes the final image more realistic.

I'm very impressed with Krea.ai

Being completely free is a huge plus, and the ability to handle distorted fingers and faces while still delivering fantastic results is truly remarkable. It makes creating content so much easier!

Krea.ai is definitely worth checking out. 

Ali Raza 

Some of the best free image upscalers are:

1. Let’s Enhance (Free Tier): Offers AI-based upscaling that preserves details and enhances textures, ideal for both personal and professional use.

2. Upscale Pics: User-friendly and reliable, it effectively enhances resolution while reducing noise and artifacts.

3. Waifu2x: Great for anime-style images and general photos, this tool excels in upscaling while minimizing noise and distortion.

4. Pixbim Enlarge AI (Trial Version): Uses AI to upscale images with a focus on clarity and detail, especially for portraits.

On the other hand Topaz Gigapixel AI is a top-tier paid upscaler, known for its advanced AI, sharpness, and detail preservation. I personally use it for my clients to ensure professional-quality results.
 

For free alternatives, tools like Let’s Enhance or Waifu2x offer effective AI upscaling but with fewer features.

I usually prefer using TOPAZ GIGAPIXEL AI, as this tool is very effective for upscaling high-quality images. However, when it comes to low-quality images, it does upscale them but retains many imperfections. In such cases, there are other tools for upscaling, like Photoshop, which offers "neural filters," including one called "zoom image" that also provides good results.

For images that have lost a lot of detail, the best option is to use certain AI services, but the results can significantly alter the original image. This can be problematic for faces or specific objects and products. However, if the image contains elements that don’t need to be exact, this approach can work well.