BARD AI was first activated on January 18, 2023

ChatGPT was developed by OpenAI and became available for public use in June 2020.

Bard is based on Bard Language Model

ChatGPT is based on ChatGPT Language Model part of the GPT (Generative Pre-trained Transformer)

Bard is Built on top of the TensorFlow framework, which is written in Python. it is. top of the neural network architecture with "federated learning" Technique. 

ChatGPT built using various programming languages and frameworks, including Python, PyTorch, and TensorFlow.

Bard is currently it is a free service.

In ChatGPT Some Of Service may have paid subscription some have Free. But at the time of high demand it is not available for free as well

Bard was built by a team of engineers and scientists at Google AI. They are Blaise Agüera y Arca, Ilya Sutskever, Oriol Vinyals, Quoc Le, and Margaret Mitchell

ChatGPT was first founded by Elon Musk, Sam Altman, Ilya Sutskever, and others

Bard uses the HTTP/2.0. HTTP/2.0 is the most recent version of the HTTP protocol.

ChatGPT uses the HTTP/2 protocol. HTTP/2 is the successor to HTTP/1.1. In addition to HTTP/2, ChatGPT also uses WebSocket, Caching, Compression

Bard has Less privacy as it will provide its own details if you will ask. it is sharing so many things related to itself 

ChatGPT Relatively keeping privacy of some data about own system