Can upscaling make a small image sharper?

Upscaling increases the pixel dimensions. Ordinary resampling estimates extra pixels from the existing ones. It cannot verify detail that the source never captured.

Enlarging a small source

A small raster image of text. — 110 × 33 source

The small image enlarged with nearest-neighbor sampling. — Nearest-neighbor enlargement

The small image enlarged with bicubic sampling. — Bicubic enlargement

The source is shown at its original size. Nearest-neighbor enlargement makes square pixels visible; bicubic makes smoother, softer edges. Neither restores the lost letter detail.

Settings and measurements

File	Dimensions	Bytes	Export settings
small-source.png	110 × 33	3,741	Optimize: True
upscale-nearest.png	660 × 198	6,057	Optimize: True
upscale-bicubic.png	660 × 198	59,138	Optimize: True

Python 3.14.4, Pillow 13.0.0, Platform Linux, Webp 1.6.0, Jpeg 6.2, Avif 1.4.2

Start with a better source

Before enlarging a thumbnail, look for the original photo, vector artwork or full-size export. Sharpening a thumbnail cannot replace a full-size original.

Check at the final size

Check the enlarged image at its final size. A result may be acceptable for a small preview and unsuitable for close reading or a large print.

AI enlargement can invent plausible-looking detail. Do not treat added letters, textures or identifying features as recovered evidence.

Related guides

Sources

Adobe: Set image size and resolution