Gemini 3.8 Flash caught 77 of 90 planted mistakes, 6th of 16 models tested. It was strongest on contradictions (14 of 15) and missed most on repeated words (10 of 15). The 4 checks took 1m 37s and cost $0.13; asked for all of them in one prompt, it caught 72.
Every comment Gemini 3.8 Flash left on our 6,000-word test story, where it left it. Click a missed mistake to find it in the text. The checks come from icanwrite, a markdown editor for writers.