THE SHORT VERSION Choose by the file you must deliver, not by the loudest model claim. Gemini is the cleanest all-round choice for a built-in 4K tier; GPT Image 2 is the stronger specification match for exact UHD and precise edits; Grok is a fast 2K ideation route that needs a finishing step for 4K. | • | Gemini 3.1 Flash Image and Gemini 3 Pro Image document built-in 1K, 2K, and 4K output; Flash also offers a 512px proof size. |
| • | GPT Image 2 accepts exact 3840×2160 and 2160×3840 requests, plus other valid dimensions within its documented limits. |
| • | Grok Imagine 2.0 currently documents 1K and 2K output, so calling a Grok result native 4K would be inaccurate. |
| • | The model with the biggest file can still lose on composition, lettering, or reference fidelity, so compare at the final display size. |
ONE · GEMINI IS THE EASIEST NATIVE-4K ALL-ROUNDER If you want high resolution without leaving the generation workflow, Gemini has the clearest answer. Google documents 1K, 2K, and 4K output for Gemini 3.1 Flash Image and Gemini 3 Pro Image. Flash also offers 512px for composition proofs. Google positions Flash as the speed-and-value all-rounder and Pro for complex professional assets. Gemini's 4K label is a resolution tier rather than a promise of the familiar 3840×2160 canvas. A square can be 4096×4096, while other ratios use different dimensions. That is excellent when you want abundant source pixels, many references, or very wide and tall ratios. It is less convenient when a production handoff demands one exact UHD canvas with no later crop. TWO · GPT IMAGE 2 WINS WHEN EXACT DIMENSIONS MATTER OpenAI's GPT Image 2 documentation lists 3840×2160 landscape and 2160×3840 portrait. It accepts other sizes when each edge is a multiple of 16, the longest edge is no more than 3840 pixels, the ratio is no wider than 3:1, and the total pixel count stays inside the published limit. That makes it a direct choice for an exact canvas. GPT Image 2 also processes image inputs at high fidelity automatically, which matters when the job is less “invent a scene” and more “keep this product, person, layout, or material while changing one thing.” The API exposes the precise size controls. A ChatGPT interface may hide some of them, so inspect the downloaded dimensions instead of assuming the app produced the API size you had in mind. THREE · GROK IS THE FAST 2K BRANCHER, NOT THE NATIVE-4K WINNER xAI currently documents 1K and 2K output for Grok Imagine 2.0, including low and medium quality modes, broad aspect-ratio choices, and multi-image editing. It does not document a native 4K output or built-in 4K upscaler. Grok can still win the creative round when it produces the best composition quickly, but the winning 2K result needs a separate resize or upscale before a 4K handoff. Use that limit deliberately. Ask Grok for four different 2K branches, choose on composition, and then decide whether the idea deserves a finishing pass elsewhere. Label the result as a 2K source enlarged to 4K. Upscaling can add plausible detail; it cannot create native source detail. FOUR · DIAGNOSTIC CHECKLIST: WHICH MODEL DESERVES THE FINAL RENDER? Start with the contract: What width, height, crop, format, transparency, and text must the asset preserve? Does the model output those dimensions directly? Does the interface expose the control, or only the API? How many references must stay recognizable? A model that answers the delivery questions is ahead of one that merely produces a pretty sample. Finish with the image, not the spec sheet. View every candidate at the actual banner, thumbnail, or screen size. Score focal hierarchy, clean edges, readable text, reference fidelity, and unwanted additions from one to five. Inspect the full-size file only after the delivery-size version passes. The winner is the image that survives the job, even if another model produced more pixels. PROMPT OF THE DAY Run this exact benchmark in Gemini, ChatGPT Images, and Grok. Request 16:9 at the highest directly supported size, then record the actual downloaded dimensions before judging the result. Create a 16:9 luxury editorial hero for a fictional fragrance named LUMEN. One frosted clear-glass bottle stands on a pale limestone plinth after rain. Center it 12% right; keep the left 36% quiet for copy; use level camera height, soft upper-left light, one controlled reflection, and a stone, silver, and lavender palette. Render exactly LUMEN and AFTER RAIN on the bottle. Preserve spelling, label alignment, geometry, edge spacing, and the empty left field. No extra words, duplicate bottles, flowers, splash, hands, logos, border, watermark, or decorative typography. DELIVERY TEST: produce the largest native 16:9 output available without an external upscale. The load-bearing line: “DELIVERY TEST: produce the largest native 16:9 output available without an external upscale.” That line separates direct model output from a later enlargement. Compare actual dimensions, spelling, reference fidelity, and composition before choosing a winner. START HERE Run the same benchmark once in each model. Save the original downloads, record their dimensions, and score the five delivery checks before doing any upscale or retouching. CHANGE ONLY: MODEL AND NATIVE OUTPUT SIZE ••• I am building a living AI image model scorecard for product shots, portraits, text-heavy graphics, and 4K campaign assets. Want the scorecard? Reply with 4K and tell me which model you want tested next. A QUESTION FOR YOU Which matters more in your 4K workflow: exact dimensions, reference fidelity, typography, or generation speed? Reply with the deliverable and your current model. I will use the most common combination in the next comparison. Forward this to someone comparing AI image models by screenshots instead of final files. Until next time, Luxe Prompting Luxe Prompting IMAGE PROMPTING AND IMAGE MODEL CRAFT Luxe Prompting · 1428 Bryn Mawr St, Scranton, PA 18504, United States Email service provider: beehiiv Privacy policy · Email preferences are available in the Beehiiv footer. |