The principles are the same (authority, structured content, consistency), but each AI has its quirks. ChatGPT tends to favor sources that appear frequently in academic and technical contexts. Gemini, being Google's, benefits directly from content that is well indexed in Google Search. Claude, from Anthropic, tends to prioritize sources with clarity and factual precision.
Perplexity is a special case: it works as a hybrid AI search engine, always citing its sources with links. That makes it the most "trackable" of the four. Showing up on Perplexity tends to happen faster because it performs search grounding on every query.
The practical recommendation is not to optimize for one specific AI. GEO best practices (quality content, schema markup, domain authority, multichannel presence) benefit all of them. If you do the fundamentals well, you show up in all of them. If you try to "hack" one in particular, you risk losing the others.