Work out how many pixels you need
Print sharpness depends on how densely pixels are laid on paper, measured in pixels per inch (ppi); print labs often say dpi. 300 ppi is the standard for photos seen at arm’s length. Posters seen from a few steps away look sharp at 150 to 200 ppi.
The math is a multiplication: print size in inches times density. An 8 × 10 inch print at 300 ppi needs 2400 × 3000 pixels. An A4 page, 8.3 × 11.7 inches, needs about 2480 × 3508. A 24 × 36 inch poster at 150 ppi needs 3600 × 5400.
A 12-megapixel phone photo, 4000 × 3000 pixels, therefore prints sharply up to about 13 × 10 inches at 300 ppi. Beyond that size, or once you have cropped the photo, upscaling fills the gap.
Choose the smallest factor that works
Pick the smallest factor that reaches your target. 2× doubles the width and the height, which means four times the pixels; 4× multiplies both by four. The 8K option sets the long side to 7680 pixels, enough for a print about 25 inches wide at 300 ppi, or a much larger poster at a lower density.
AI upscaling does not stretch pixels like a classic resize. It predicts plausible detail, such as skin texture, foliage or brickwork, from what it has learned on similar images. That is why the result looks sharper than a standard resize, and also why it can invent detail that was never there.
Each upscale uses one credit, and two at 8K. An 8K result takes a few seconds longer than the usual five, because there are many more pixels to compute.
Prepare the file before upscaling
Upscale the original, not a screenshot or a copy sent through a messaging app. Recompression wipes out the fine detail the upscaler relies on. If the original is HEIC, upload it as it is: it is converted without loss.
Crop first, then upscale. Cropping afterwards spends credits and processing time on pixels you will throw away, and a tighter crop often lets you pick a smaller factor.
If the photo is also damaged, with scratches or faded colors, restore it before you upscale. Repairs are more accurate at the original size, and the upscaler then builds on clean detail instead of enlarging the scratches.
Check for artifacts at 100%
Zoom to 100% and scan the photo section by section. Typical upscaling artifacts are waxy skin, repeated patterns in grass or hair, wobbly straight lines and letters turned into lookalike shapes. If a sign or a label must stay readable, compare it with the original.
Step down a factor if a 4× result looks artificial. A 2× upscale printed at 240 ppi often looks more natural than a 4× upscale at 300 ppi: viewers notice fake texture much sooner than slight softness.
Noise and JPEG blocks get enlarged along with everything else. The Denoise option smooths them before upscaling; leave it off for film scans, where the grain is part of the picture.
Export for the printer
Export as PNG or as a maximum-quality JPG. Most print labs expect JPG files in the sRGB color space; ask before sending anything else, because color conversions are where prints most often go wrong.
The pixel dimensions are what matter. If the lab asks for 300 dpi, set the value in the export or in its upload form: it does not change a single pixel, only the size at which the file prints by default.
Before an expensive large format, order a small test print of a crop at the final size. It costs little and shows exactly how the upscaled detail holds up on paper.
Frequently asked questions
What is the largest size I can upscale to?
8K, which means 7680 pixels on the long side. You can start from any JPG, PNG, WebP or HEIC photo up to 25 MB.
Can I upscale a small image from the web?
Yes, with limits: a 400-pixel thumbnail holds very little real detail, so an 8K result has to invent most of it. Use 2× or 4×, and check faces and text at 100%.
Do I always need 300 dpi?
No. 300 ppi suits prints seen up close. Posters and banners viewed from a distance look sharp at 150 ppi, which halves the pixels needed on each side.
