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. On September 3, 2026 OpenAI shipped GPT-6 Astra – a new generation of intelligence topping FrontierMath, ARC-AGI-3, and ExploitBench. On September 22, 2026 OpenAI shipped GPT-6 Sol and Luna – Astra-trained efficiency tiers at half the API price ($2/$10 and $0.10/$0.50), rolling to Work, Codex, and the API. On September 29, 2026 OpenAI shipped GPT-6.1 Sol at DevDay – near-Astra coding intelligence at a fifth of Astra’s token price, with cached reads halved to $0.10.
In this guide we explain what ChatGPT is in 2026, how the GPT-6 Astra, 6.1 Sol, and Luna 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-6 Astra, 6.1 Sol, and Luna
ChatGPT now runs on GPT-6 Astra, rolling out September 3, 2026 as a new generation of intelligence beyond the 4T Spud base shared by GPT-5.5 and GPT-5.6. Astra is OpenAI’s first model at the Critical cyber threshold and saturates FrontierMath Tier 4 (98%), ARC-AGI-3 (99.9%), and ExploitBench (100%). You rarely pick by hand – ChatGPT auto-routes between fast and deliberate responses, with Astra rolling to all Plus, Pro, Business, and Enterprise users over the coming days.
On September 22, 2026 OpenAI added GPT-6 Sol and Luna: the same Astra-trained methods in faster, cheaper tiers at half the API price – Sol at $2/$10 with AutomationBench 33.2% and DeepSWE 68.8%, Luna at $0.10/$0.50 matching GPT-5.6 Sol at about a hundredth of the cost. Both roll to Work and Codex for paid plans, Luna also to the desktop app for Free and Go users, and to the API as gpt-6-sol and gpt-6-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.
GPT-6 Astra rolls out to Daybreak cybersecurity program, then to all Plus, Pro, Business, and Enterprise over the coming days, and via API as gpt-6-astra on Azure and Bedrock. $10/$50 per 1M input/output, Fast mode 2x speed at 2x price, Critical cyber threshold, 100% ExploitBench.
GPT-6 Sol and Luna ship at half the API price ($2/$10 and $0.10/$0.50): Astra-trained efficiency tiers with AutomationBench 33.2%, DeepSWE 68.8%, and about half the factual mistakes. Work and Codex for paid plans, Luna in the desktop app for Free and Go, API as gpt-6-sol/gpt-6-luna; not yet in Chat.
GPT-6.1 Sol ships at DevDay at the same $2/$10 as GPT-6 Sol with cached reads halved to $0.10: near-Astra coding with DeepSWE 75.2% and OSWorld 71.4%, 1.1M context, and about $5.47 average task cost vs $23-plus for Astra. In Work, Codex, and the API as gpt-6.1-sol; prompts over 272K tokens bill higher for the whole request.
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-6 Astra and GPT-5.6 families support context windows of up to about 1 million tokens – roughly 750,000 words – for Astra, GPT-5.6 Sol, and Terra, and 400,000 tokens (about 300,000 words) for GPT-5.6 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. Leaks cited 1.5M for GPT-6, but OpenAI documents 1M as GA.
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-6 Luna | Unlimited everyday text chat; capped use of Deep Research, file uploads, voice, image generation, and browsing |
| ChatGPT Go | from $3/mo | GPT-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-6 Astra, Sol and Luna (Work/Codex), GPT-5.6 legacy | 5x higher limits than Free: full Deep Research, Work with file and app access, advanced voice, image generation, Projects, memory, custom GPTs |
| Pro | $200/mo | GPT-6 Astra + Pro, GPT-6 Sol and Luna, GPT-5.6 legacy | Unlimited access to the most capable tools and models, including extended agentic work and priority support; Astra included in subscription allowance |
| Business | $30/user/mo | GPT-6 Astra | Privacy-guaranteed business use, admin controls, team workspace, no training on company data; rolling Sep 2026 |
| Enterprise | Custom | GPT-6 Astra | Scaled-up governance, security, and analytics with unlimited access; Daybreak cyber program first, then phased |
| API | usage-based | gpt-6-astra $10/$50 · gpt-6.1-sol $2/$10 ($0.10 cached) · gpt-6-luna $0.10/$0.50 per 1M | Fast mode 2x speed at 2x price; Zero Data Retention eligible |
GPT-6 Astra rolls out first to Daybreak cyber program, then to all paid ChatGPT plans over the coming days and via API (gpt-6-astra) on OpenAI, Azure, and Bedrock. API Standard pricing $10/$50 per 1M input/output, Fast mode 2x. GPT-6 Sol and Luna (Sep 22) roll to Work and Codex for Plus, Pro, Business, Enterprise, and Edu, Luna also to the desktop app for Free and Go users, and to the API; neither is in Chat yet and rollout is gradual through the day. GPT-6.1 Sol (Sep 29) keeps $2/$10 with $0.10 cached reads; prompts over 272K tokens bill higher for the whole request. Deep Research is included in all plans. The chart above reflects September 2026.
Frequently asked questions
Heads-up:ChatGPT is a fast-moving product. Plan names, model names, and prices change frequently – the details above reflect September 2026 (Astra Sep 3; Sol/Luna Sep 22; 6.1 Sol Sep 29). Check the official ChatGPT site and system card for current availability and limits.