Did your AI upscale actually add detail? Here is how to check
Upscalers all promise more detail. Some deliver it. Others just make the image bigger and a little softer, then hand it back at a higher resolution so it feels like something happened. If you cannot tell which one you got, you cannot tell whether the tool is worth using. The good news is that it takes about ten seconds to check.
Bigger is not the same as sharper
There are two very different things an upscaler can do. It can genuinely reconstruct detail, sharpening edges, recovering texture, and cleaning up text. Or it can interpolate, which is a fancy way of saying it fills the new pixels by averaging the old ones. Interpolation makes the file larger without adding real information, and the result looks soft.
Here is what that difference actually looks like. On the left is a plain bicubic upscale, the interpolation kind. On the right is the same scene with real detail. Same size, very different result. Drag the divider and watch the edges and the fine rings:
Once you have seen it under a slider, you cannot unsee it. The soft version is not “lower quality,” it is missing information that the sharp version has.
How to test your own upscale
- Keep your original, lower resolution image.
- Run it through your upscaler of choice and save the result.
- Downscale the upscaled version back to the original size, or upscale the original with plain bicubic, so you are comparing at a matched size.
- Drop both into a before and after slider and look hard at the places detail hides: text, hard edges, hair and fur, foliage, and skin texture.
If the upscaled side has crisper edges and readable text where the plain version is mushy, the tool added real detail. If both look about the same except one is softer, you paid for interpolation.
What actually adds detail
Modern AI upscalers like Topaz Gigapixel are built to reconstruct detail rather than just enlarge, which is why they hold up under exactly this kind of slider test. Plain resamplers and a lot of the free “make it bigger” tools do not. The slider is how you tell them apart before you commit to one, and it is worth doing on your own images since results vary a lot by content.
Do it with your own images
Guessing from a thumbnail is how you end up trusting an upscaler that is not doing much. Line the two versions up and drag. Make your own comparison on imgi, free and with no signup, and if you want a bit-exact look with no recompression, use the offline mode so you are judging your real files.