Gemini 3.1 Pro vs 3.7 Flash: a magazine or an app

Both of these were told they had complete creative freedom and a $10,000 fee, and they went in opposite directions with it. 3.1 Pro built a magazine: 781 lines, four case studies, an enormous display face and almost nothing else. 3.7 Flash built an application: 3,530 lines, a costing tool, a case-study drawer, filters, world clocks, a sound toggle and a brief form. The plainest way to say it is that the first one ships zero buttons and zero inputs, and the second ships twenty-one buttons and six inputs.

The size follows from that and so does the length of the page. 24 KB against 125 KB, and at a 1440 px window the first is 4,822 px tall and the second 9,486 px — twice the homepage, on a brief that asked for one.

Where they differ most is what they did about pictures. 3.1 Pro's portfolio is three photographs from Unsplash, and they are stock in the way stock always is: the spatial-computing case study is illustrated with a Commodore and a stack of cassette tapes. Block the network and all three frames are empty, which for a page whose brief began “Single HTML file” is the answer to whether it is one. 3.7 Flash fetched no images at all. It drew twenty-four pieces of inline SVG instead — a mark for each case, each service, each proof point — and offline it loses its typeface and nothing else.

3.7 Flash also says it tested the result, and that shows in the one place it would. The Scope Engine is not a decorative slider: tick another capability and the estimate moves from $54,000 to $76,000, ask for the compressed timeline and it goes to $98,800, and the button underneath carries the number into the brief form further down the page. The case drawer opens and fills with the right project. For a feature invented on the spot by a model that was not asked for it, it is wired all the way through.

What it is not is restrained, and that is the whole disagreement. The brief said to avoid AI design clichés. Neither page has the purple gradient, but a homepage with a quote engine, a filter bar, four time zones and an audio toggle on it is its own kind of tell: it is what a model builds when it is trying to prove the fee. 3.1 Pro spent the fee on one thing — the type — and left the rest of the page empty on purpose, which is what the expensive agency sites it is imitating actually do.

Only one hard fault turned up between them, and it is in the one we prefer: below about 750 px of window height, 3.1 Pro's “open for new projects” badge slides up under the fixed wordmark and the two print on top of each other — at 1440×700 they overlap by 22 px. Give the window 60 px more and it clears. Neither page scrolls sideways at 390, 768 or 1440 px, and both of them still fetch their typefaces from Google, so neither is the single file the brief asked for.