What is ChatGPT and how it can help you be more productive
ChatGPT isn’t really a single chatbot anymore. What launched in November 2022 as a research preview on top of a fine-tuned GPT-3.5 model has grown into a full AI platform: a conversational assistant, a research tool, a coding partner, and now an agent that can carry out multi-step work on its own.
In this guide we explain what ChatGPT is in 2026, how the GPT-5.6 model family works, what ChatGPT Work, Deep Research, and Codex can do, what the plans cost, and how to use it well.
What is ChatGPT?
ChatGPT is an AI assistant developed by OpenAI. At its core it uses large language models to understand natural-language instructions and generate human-like responses. What has changed since 2022 is everything around that core: web search, deep research, file and data analysis, image generation and editing, real-time voice, memory, Projects, connected apps, and agentic modes that keep working until they deliver a finished result.
Today ChatGPT is not just an answer engine. Depending on the plan and the task it can:
- Answer questions & explain concepts
- Write, rewrite & summarize
- Search the live web
- Run deep research with citations
- Analyze files, spreadsheets & data
- Generate & edit images
- Write, debug & review code
- Talk back in real time
- Work with your connected apps
- Finish multi-step tasks as an agent
GPT-5.6: Sol, Terra, and Luna
ChatGPT runs on OpenAI’s GPT-5.6 family, generally available since July 9, 2026. The generation number marks the capability baseline; the names mark three durable tiers that OpenAI can keep improving on their own schedule. You rarely pick one by hand – ChatGPT auto-routes between fast and deliberate responses, and in August 2026 Plus and Pro moved to a unified GPT-5.6 Sol experience while Free and Go users got unlimited everyday text chat on Luna.
How does ChatGPT work?
GPT models are neural networks trained on enormous amounts of text, code, images, and audio to recognize patterns and predict the most plausible next part of a response. Since GPT-5, the chat experience also decides how much to “think”: trivial questions get an instant answer, while hard ones trigger deliberate step-by-step reasoning before a response is generated.
Modern ChatGPT goes beyond text prediction by combining the model with tools. A typical request flows through several stages:
- 1
Understand the request
The model reads your prompt and the conversation context, including memory and anything you uploaded.
- 2
Reason through the problem
For complex tasks it works through the problem step by step instead of generating an answer in one pass.
- 3
Decide which tools to use
When needed, it searches the web, runs deep research, analyzes files, executes code, or calls your connected apps.
- 4
Generate the response or take the action
It produces the answer, the document, the chart, or the finished deliverable you asked for.
- 5
Refine with follow-ups
You push back, narrow the scope, or redirect, and the same thread keeps the context.
What can you do with ChatGPT?
The agentic shift: Work, Deep Research, Codex
The biggest change since 2023 is not that answers got better – it is that ChatGPT moved from conversation toward execution. Instead of “you ask, it answers,” the workflow is increasingly “you define a goal, ChatGPT researches, analyzes, uses tools, and comes back with something finished.”
OpenAI has also been consolidating its product surface. The standalone Atlas browser was retired on August 9, 2026, with browsing folded into the ChatGPT desktop app and a Chrome extension; the standalone Sora video app was shut down in April 2026. The strategy is fewer surfaces – Chat, Work, Codex – that each do more.
ChatGPT timeline: 2022–2026
Public research preview launches on a fine-tuned GPT-3.5; 100 million weekly users arrive within two months – the fastest consumer app growth at the time.
GPT-4 powers ChatGPT Plus; tool plugins and browsing arrive. The same month sees the first wave of enterprise interest.
GPT-4o adds real-time voice, vision, and images to the free tier – the first big multimodal release.
o1 introduces chain-of-thought reasoning; ChatGPT reaches 200 million weekly users.
Deep Research ships; the first true agentic capability. By the end of the month ChatGPT passes 400 million weekly users.
ChatGPT passes 800 million weekly users; its iOS app becomes the most-downloaded free app in the US App Store.
ChatGPT Go launches with pay-as-you-go access; the user base crosses the 1 billion weekly mark in May.
GPT-5.6 family ships (Sol, Terra, Luna) with unified access across tiers; ChatGPT Work launches as an agentic mode for all plans.
The Atlas browser is retired and folded into the desktop app; Plus and Pro move to a unified GPT-5.6 Sol experience.
How to use ChatGPT well
The prompt pattern that works
Role, task, format – the same structure powers everything from emails to investment memos. For bigger asks, share examples of the output style you like; for long-running work, put files and instructions in a Project so every chat starts with the right context.
How large is the context window?
The GPT-5.6 family supports context windows of up to 1 million tokens – roughly 750,000 words – for Sol and Terra, and 400,000 tokens (about 300,000 words) for Luna. That is enough to hold entire books, full codebases, or hundreds of pages of documents in a single session, and to keep working across multi-hour research and agent runs.
Practical rule of thumb: a token is roughly 0.75 English words, and about 1.5 tokens per word once you factor in punctuation and spacing.
What does ChatGPT cost?
| Plan | Price | Model access | Limits |
|---|---|---|---|
| Free | $0 | GPT-5.6 Luna | Unlimited everyday text chat; capped use of Deep Research, file uploads, voice, image generation, and browsing |
| ChatGPT Go | from $3/mo | GPT-5.6 Luna | Pay-as-you-go top-ups that unlock premium features without a subscription; $3 tier covers around 60 minutes of voice a month |
| Plus | $20/mo | GPT-5.6 Sol (unified), GPT-5.6 Terra | 5x higher limits than Free: full Deep Research, Work with file and app access, advanced voice, GPT-4o and DALL-E image generation, Projects, memory, custom GPTs |
| Pro | $200/mo | GPT-5.6 Sol (unified), GPT-5.6 Terra | Unlimited access to the most capable tools and models, including extended agentic work and priority support |
| Business | $30/user/mo | GPT-5.6 Sol | Privacy-guaranteed business use, admin controls, team workspace, no training on company data |
| Enterprise | Custom | GPT-5.6 Sol | Scaled-up governance, security, and analytics with unlimited access for large organizations |
Deep Research is included in all plans, with free access for research universities and non-profits. Prices and included limits change over time; the chart above reflects August 2026.
Frequently asked questions
Heads-up:ChatGPT is a fast-moving product. Plan names, model names, and prices change frequently – the details above reflect August 2026. Check the official ChatGPT site for current availability and limits.