Upscale to
Upscale an image to 4K
4K is a pixel count, not a quality setting: 3840 × 2160 for UHD, 4096 × 2160 for the cinema variant. What your file needs is arithmetic, and the answer is almost always a single pass.
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Recommended setup
Start with Ultra Upscale 8X.
Maximum resolution and detail, up to 8×.
- Upscale
- 4×
- Detail strength
- 0.5
Best for: Product photos · portraits · print-size enlargements
4K is a pixel count
It is worth being blunt about this, because "4K" is sold as a quality tier and is actually just a number. 4K UHD is 3840 × 2160. DCI 4K, the cinema variant, is 4096 × 2160. Everything else follows from the long edge.
An image is 4K when its long edge reaches 3840 px. Nothing about sharpness, colour or noise is implied — a soft, noisy 4K file is still 4K, which is why "upscale to 4K" and "make this look good" are two different requests. This page is about the first one; if your source is damaged, clean it first and then read on.
The arithmetic
Divide 3840 by your current long edge, then round up to a pass that exists:
| Your long edge | Factor needed | Pass to use |
|---|---|---|
| 1920 px | 2.0× | 2× |
| 1280 px | 3.0× | 4× |
| 1024 px | 3.75× | 4× |
| 960 px | 4.0× | 4× |
| 640 px | 6.0× | 8× |
| 480 px | 8.0× | 8× |
Two things people get wrong here. The first is measuring the display size rather than the pixel size — a phone showing an image at 390 points wide says nothing about the file. The second is portrait orientation: 4K is the long edge, so a 2160 × 3840 image is 4K, and a portrait file needs its height to reach 3840.
One pass, not a chain
The most common mistake is running 2× twice to get 4×. It seems equivalent and is not.
An upscaler reconstructs plausible detail from what it can see. On the first pass, "what it can see" is your photograph. On the second, three quarters of the pixels it is reasoning about were invented by the first pass — so it confidently sharpens its own guesses. Two passes produce a characteristic over-defined look, and repeating texture patterns that read as machine-made from across a room.
Pick the smallest single pass that clears 3840 and stop there.
Pro tips
- Do not overshoot. 8× when 4× would do costs the same 3 credits and gives the model more freedom to invent. Bigger is not safer.
- Clean before you enlarge. A noisy or compression-damaged source should go through Unblur & Restore first; 4K noise is still noise, just more of it.
- For print, ignore 4K entirely. It is a screen standard. A print is specified in inches and DPI, and 3840 px is 12.8 in at 300 DPI — beyond that, work backwards from the finished size.
- Cost: Ultra Upscale 8X is 3 credits at any scale, so the scale you pick changes the result, not the price.
FAQ
Questions, answered.
What counts as 4K?
4K UHD is 3840x2160 and is what screens, TVs and video platforms mean. DCI 4K is 4096x2160 and is a cinema standard. Both are measured on the long edge, so a portrait image needs 3840 px on its height.
What scale do I need?
Divide 3840 by your current long edge and round up to 2x, 4x or 8x. A 1920 px image needs 2x; 1280 px needs 3x, so take 4x; anything under 960 px needs 8x.
Is two 2x passes the same as one 4x?
No, and it is worse. The second pass treats the first pass's invented detail as ground truth, so errors compound. One pass at the scale you need, every time.
Does 4K mean it will print well?
Only at a size. 3840 px is 12.8 inches at 300 DPI. For anything larger, work from the printed size instead — the print size calculator does that arithmetic.
See it on your own image.
3 images on signup, watermarked. Plans from ₹1,499/month.