Why does generating above a model's native resolution cause problems?

Diffusion models learn composition at their training resolution. Pushing SD 1.5 past 512px or SDXL past ~1MP in a single pass often produces duplicated heads, limbs, or repeated patterns because the model has no concept of the larger canvas. Tiled diffusion or upscaling avoids this.

What is the highest native resolution available?

Among the listed models, Flux handles roughly 2 megapixels (about 2048×2048 equivalent area) cleanly. SDXL is native at 1MP. For larger outputs you generate at native size then upscale 2x-4x with a dedicated upscaler.

Can DALL·E 3 produce custom dimensions?

No. DALL·E 3 only offers three fixed sizes — 1024×1024, 1792×1024, and 1024×1792. If you need an arbitrary aspect ratio you must crop or outpaint afterwards.

Does this tool generate images?

No. It is a reference calculator that compares model resolutions and tells you when upscaling is needed. All computation runs locally in your browser.

Image Resolution Comparison Tool

AI image resolution comparison

Every text-to-image model has a native resolution it was trained at, and output quality drops sharply when you stray far from it. This tool lets you enter the final size you need and immediately see which of the major models — SD 1.5, SDXL, Flux, DALL·E 3, and Midjourney — can produce it directly, which need an upscaling pass, and which require tiled diffusion to reach the target without artifacts.

How it works

You enter a target width and height. The tool calculates the megapixel count (width × height ÷ 1,000,000) and compares it against each model’s native megapixel area. If your target is within about 10% of a model’s native area it flags it as generate-directly. Up to roughly 2x it recommends a standard upscale; beyond that it recommends tiled diffusion or a multi-step upscale chain, because a single oversized pass would likely duplicate features.

Notes and tips

Match aspect ratio too. Megapixels are only half the story — a 1920×1080 target is the same area as 1424×1424, but the wide framing still matters for composition.
Generate native, then upscale. The cleanest workflow is almost always to render at the model’s trained resolution and upscale with a dedicated model like 4x-UltraSharp rather than forcing a huge first pass.
Flux for large single-pass. When you genuinely need ~2MP in one shot without tiling, Flux is the most reliable of the listed models.
DALL·E 3 is fixed-size. Plan around its three presets; there is no custom dimension input.