Stable Diffusion image detector
last updated 7 june 2026
Stable Diffusion is open-source, so its output spans thousands of community fine-tunes (SDXL, SD3 and countless custom models) with wildly varying quality — from photorealistic to obviously synthetic. That variety makes visual tells less consistent, so a detector plus careful inspection is the reliable combination.
Because Stable Diffusion runs locally and can be fine-tuned by anyone, there's no single "Stable Diffusion look" and no central watermark you can count on. You'll see everything from polished SDXL renders to glitchy outputs from niche checkpoints — which is exactly why a single rule of thumb won't cover it.
verifai takes the model-agnostic approach: it scores the images actually on the page rather than trying to name the checkpoint, and highlights the ones that read as likely AI.
What to look for
Quality varies, but the diffusion fingerprints persist across most Stable Diffusion variants:
- anatomical glitches — hands, teeth, overlapping limbs
- background incoherence and warped fine detail
- fabric and pattern drift across the image
- a plastic or over-sharpened texture on skin and surfaces
Why open-source is harder to detect
Custom fine-tunes can deliberately erase a generator's usual signatures, and local generation means no provenance metadata is added at all. There's no SynthID, no C2PA — nothing to read. In that environment, an automated detector and a human eye, used together, are your best signal.
frequently asked
Does Stable Diffusion add a watermark?
The reference pipeline includes an optional, easily-removed watermark, and most local or fine-tuned setups don't apply a durable one. In practice you can't rely on a watermark for Stable Diffusion images.
Can verifai detect SDXL and custom models?
verifai is model-agnostic: it scores how AI-like an image looks rather than identifying the exact model, so it applies to SDXL, SD3 and community fine-tunes alike.