30 thumbnail concepts: draft at low, upscale 3 winners for $1.34

Thirty thumbnail concepts drafted at GPT Image 2.5 low cost 30 x $0.02475 = $0.7425. Upscaling the 3 you pick adds 3 x $0.20 = $0.60, so the whole test costs $1.3425. Rendering all 30 at the high tier would be 30 x $0.2225 = $6.675, and upscaling every draft would be $6.7425.

The funnel

The idea is to spend the small amount on breadth and the large amount on a few finalists. A draft shows composition, face placement, text size and color contrast. These do not change when you upscale, so a concept that wins at draft size is still the winner at 3840 x 2160. Detail that only appears at high quality, such as skin texture, is what you give up in review.

Reading the table

The first row is the cheapest way to get three large finals. The medium row is close at $1.66875 and gives you 30 medium images, so if you do not need 4K, you can stop there. The upscale-all row is slightly dearer than rendering at high, which means that you should never upscale the whole set. Upscale the finalists.

YouTube's help page recommends 3840 x 2160 for video thumbnails and keeps mobile uploads to 2 MB. Save the finalists as JPG if they come out larger than that.

Picking the three

Put the 30 drafts on one contact sheet and look at them at the size of a phone thumbnail. A good concept reads in under a second: one face or object, three or four words of text, strong contrast. Drop any draft that you have to squint at.

Pick winners before anyone sees the real video title, or you will choose thumbnails that fit the title and not the click. If you want to test them live, YouTube's own test tools are the next step. The upscale of three finalists is $0.60, so it is cheap to redo with a different set if the first test is flat. The media price sheet lists the same unit prices for larger volumes.

Scaling the funnel

The same shape works at other sizes. For 100 concepts, drafts are $2.475, and upscaling 5 finalists adds $1.00, so the test costs $3.475. For 12 concepts and 2 finalists, it is $0.297 + $0.40 = $0.697.

The more concepts you draft, the more the draft price matters and the less the finalist price does. Because the draft price is under three cents, breadth is nearly free. The finalists carry the cost, so keep their number small and chosen on purpose.