Photo AI: How Pieter Levels Turned a Stable Diffusion Fine-Tune into a $100k-a-Month Solo Business
The one-line version: a solo developer fine-tuned Stable Diffusion on people's selfies, wrapped it in a plain PHP site, and grew it to a publicly reported $100,000 a month in about 18 months, with no employees and no investors.Pieter Levels is not a designer or an ML researcher. He is a builder who…
The one-line version: a solo developer fine-tuned Stable Diffusion on people's selfies, wrapped it in a plain PHP site, and grew it to a publicly reported $100,000 a month in about 18 months, with no employees and no investors.Pieter Levels is not a designer or an ML researcher. He is a builder who already had an audience from Nomad List and Remote OK, and he treated image generation the way he treats everything: ship the ugliest working version fast, charge from day one, and post the numbers.Timeline, as reported by LevelsOctober 2022: first experiments with Stable Diffusion fine-tuning. An earlier viral project, Avatar AI, had shown that people would pay for AI photos of themselves.10 February 2023: Photo AI launches. Around $5,400 in revenue in the first week.April 2023: roughly $28,700 for the month.July 2023: roughly $61,800 for the month.February 2024: about $77,000 a month.September 2024: passes $100,000 a month.2025: revenue around $132,000 a month is posted publicly; Levels has since shared lower figures in the $105,000 range as annual plans and churn even out.That last point matters. Photo AI's number moves month to month, and Levels reports gross revenue, not profit. The direction is what counts: an image product built by one person, still growing three years in.What he actually builtThe model: personalised models trained per customer. Early versions used Stable Diffusion 1.5 with DreamBooth-style fine-tuning; later versions moved to SDXL. He tested Flux and, by his own account, removed it.The infrastructure: training and inference on Replicate, costing roughly $12,000 a month at scale. The website itself is a single large PHP file with a SQLite database on one server.The product: upload 10 to 20 selfies, wait for training, then generate photoshoots in any style. Pricing runs from a $19 starter tier to $199 for heavy users, and most revenue comes from the $49 to $99 tiers.The margin: with compute around $12,000 to $13,000 a month against six-figure revenue, the reported margin is above 85 percent.Where the customers came fromAbout half of traffic came from X, where Levels posts revenue screenshots, model comparisons and failures in public. Organic search and direct visits made up most of the rest. A single appearance on the Lex Fridman podcast produced a visible spike. There was no paid acquisition of note.What a creative person can copyThe model is not the moat. Photo AI runs on open weights anyone can download. The moat is the wrapping: a clear promise ("photorealistic photos of you"), a training flow non-technical people can complete, and a price attached from the first day.Compute is a cost of goods, not a research budget. Levels rents GPUs per job on Replicate and prices the product so that a paying customer covers their own training run with margin left over. If you sell AI images, know your cost per generation before you set a price.Post the number. The revenue screenshots were the marketing. For a solo creator, transparency is cheaper than ads and compounds for years.Where these numbers come fromEvery figure above is self-reported by Pieter Levels on X or in interviews, and compiled from the Indie Hackers case study, ppc.land's May 2025 analysis, and the Lex Fridman podcast interview. Aituts has not audited them. Where sources disagree on a month, we have used the later, more conservative figure.