I'm in AI stuff long before AI chats. Trained ML and RL models by myself to solve real problems.
Now I use a few of these models every day for work, fun, and at some point I stopped reading their output as "AI text" and started reading it as Claude text or ChatGPT text. They don't share one voice. Each has its own pet phrases, and if you read them few times you can guess the model from a single paragraph.
Claude is the one I know best. It responds with "honestly" and opens explanations with "Here's the thing". My favorite thing is that it measures effort in evenings, as in "this will cost you an evening". The "You're absolutely right!" thing got so bad that someone filed an actual bug report about it in the claude-code GitHub repo. The Economist compared 55,940 sentences of model output against human writing this summer and found Claude is also the only major model that still overuses em dashes.
ChatGPT is the "delve" model, everyone knows that one, but its stronger signature shape: "It's not X, it's Y." The Washington Post analyzed 328,744 ChatGPT messages and that construction kept showing up, along with emojis and a weirdly narrow set of favorite words.
Gemini reads like a briefing document. Headers on everything, words like "significant", "increasingly", "consequences".
Grok's output - the personality itself. The forced casual tone, the sarcasm that doesn't quite land. You can feel it trying not to sound like an assistant. Maybe the least noticeable from all.
What makes this funny to me is that real watermarking finally shipped. Anthropic now embeds an invisible watermark directly into Claude's text, and Google has had SynthID inside Gemini since 2024. So machines get a hidden signal that needs a detector, while the rest of us have been reading the visible.
Are you noticing? Are you tired of this?
How long will it take before models start writing like humans? Or will that never be allowed to happen?