ChatGPT vs. Jurassic

ChatGPT

ChatGPT is OpenAI's consumer and business AI product, powered by the GPT model family. GPT-5.6 is the current generation for advanced reasoning, coding, computer use, and professional work.

ChatGPT launched in November 2022 on GPT-3.5 and later added GPT-4, GPT-4o, the o-series reasoning models, and GPT-5. OpenAI released GPT-5.6 in July 2026 across ChatGPT, Codex, and the API. The generation includes the flagship Sol tier, the balanced Terra tier, and the fast, cost-efficient Luna tier. GPT-5.5 Instant remains available for fast everyday conversations, while GPT-5.6 powers higher-effort reasoning options on eligible plans.

Further reading

• openai.com/blog/chatgpt
• openai.com/research/instruction-following
• openai.com/index/introducing-gpt-5-5/
• openai.com/index/gpt-5-6/

Jurassic

Developed by AI21, a startup founded by luminaries from Stanford and Mobileye, Jurassic was one of the first LLMs to challenge GPT-3. While it includes some support for code, Jurassic is more focused on reading and writing use cases, perhaps linked to AI21's development of other tools such as Wordtune. Jurassic also introduced the MRKL system for interfacing with external, non-neural modules.

Further reading

• www.ai21.com/blog/jurassic-x-crossing-the-neuro-symbolic-chasm-with-the-mrkl-system