ChatGPT (GPT-3.5)

GPT-3.5, which powered the original free tier of ChatGPT, is faster but less capable than GPT-4 at complex reasoning, nuanced writing, and multi-step coding tasks. ChatGPT Plus subscribers gained access to GPT-4 (and later GPT-4o), which offered significantly improved instruction-following, larger context windows, and multimodal capabilities like image analysis not available in the free GPT-3.5 tier.

The original GPT-3.5-based ChatGPT launched in late 2022 without internet access, meaning its knowledge was frozen at a training data cutoff. OpenAI later added web browsing capabilities to ChatGPT, but feature availability on the free tier has evolved over time, so users should check their current interface for a browsing option.

GPT-3.5 can draft functional code snippets in popular languages like Python, JavaScript, and SQL for straightforward tasks such as parsing files or writing SQL queries. However, it frequently makes errors on complex multi-file architecture, subtle debugging, and edge-case handling, where GPT-4 and later models demonstrate markedly better accuracy.

By default, OpenAI may use conversations from the free ChatGPT tier to improve its models through training, but users can opt out by disabling chat history in their account settings. ChatGPT Plus, Team, and Enterprise plans offer greater data privacy protections, including opt-out from training by default on certain tiers.