ChatGPT is OpenAI's conversational AI platform, available at chatgpt.com and via mobile apps, offering a tiered set of plans from Free to Enterprise that unlock progressively more powerful models, tools, and context. For everyday users, mastering its layered feature set — memory, projects, voice, file uploads, agents, and prompt patterns — turns it from a simple Q&A tool into a persistent, customizable productivity assistant. The single most important mental model: the model does not know your context unless you give it, so investing in custom instructions, project workspaces, and saved memories pays back every session.
What This Cheat Sheet Covers
This topic spans 20 focused tables and 138 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.
Table 1: Plans and Account Tiers
The 2026 ChatGPT lineup spans six tiers with meaningfully different model access, usage limits, and privacy controls. Understanding which plan unlocks which feature prevents the common frustration of expecting a premium feature on a Free account.
| Plan | Example | Description |
|---|---|---|
$0/mo; GPT-5.5 Instant (limited), 27K context, 3 file uploads/day, 2 hrs voice/day | • Entry tier • covers basic chat, limited web search, limited image generation, and access to the GPT Store for browsing (not creating) GPTs | |
$8/mo; more messages and uploads, 54K context, voice with video, no data training opt-out required | • Mid-tier between Free and Plus • may include ads • adds expanded voice and context window over Free | |
$20/mo; GPT-5.5 Thinking access, tasks, custom GPTs, 25 files/project, 54K context | • Most popular paid tier • unlocks Tasks, Advanced Data Analysis, Canvas, image generation with Thinking, and projects with up to 25 uploaded files |