GPT-trainer is an AI chatbot builder that allows users to create custom chatbots without coding. The platform uses OpenAI's GPT-3.5 and GPT-4 large language models to generate responses based on uploaded data, URLs, or direct text input. The chatbots can be embedded on websites or used in Slack. GPT-trainer offers various pricing plans for individuals and enterprises, with add-ons for additional message credits. The platform prioritizes security and privacy, with strict measures to prevent data loss and unauthorized access.