The best model depends on what you are trying to do. The selector in Chatex AI lets you switch quickly, so it is normal to try more than one model for the same task.
Quick guide
GPT models: a strong default for everyday writing, coding, and general-purpose chat.
Claude models: often strong for long-form writing, summarization, and nuanced reasoning.
Gemini models: useful for multimodal workflows, research, and longer-context tasks.
DeepSeek, Qwen, Kimi, Mistral, and Grok: useful alternatives when you want a different reasoning style, faster replies, or a better fit for a specific prompt.
If the answer quality is off, try another model family before rewriting your whole prompt. Attachment support, audio input, and other multimodal features can also vary by model.