ChatGPT

ChatGPT is OpenAI’s flagship AI assistant and the product that ignited the generative AI revolution. Launched on 30 November 2022, it reached 1 million users in just 5 days—the fastest-growing consumer application in history. As of October 2025, ChatGPT commands 800 million weekly active users and processes over 2.5 billion queries daily.

The platform now runs on GPT-5.1 (released November 2025), offering everything from casual conversation to advanced research, image generation, real-time voice chat, and agentic web browsing. Whether you’re a casual user on the free tier or a power user paying $200/month for Pro, this guide covers everything you need to know.

Quick stats

Pricing breakdown

ChatGPT offers five tiers, each targeting different use cases and budgets. All prices are in USD.

Free — $0

The free tier is genuinely useful, not just a demo. You get:

• GPT-4o mini — Unlimited messages with OpenAI’s efficient model
• Limited GPT-5 — Approximately 10 messages every 5 hours
• 1 GPT-5-Thinking message per day — For complex reasoning tasks
• Web browsing — Search the internet for current information
• 5 Deep Research queries/month — Agentic research that synthesises multiple sources
• Basic voice mode — Talk to ChatGPT (GPT-4o mini voice)
• File uploads — 3 files per day, 2M token limit for text

Limitations: No image generation, restricted access to advanced models, slower during peak hours, no Custom GPTs creation (but you can use others’ GPTs).

Worth it for: Casual users, trying before buying, students, anyone wanting a capable free AI assistant.

Plus — $20/month

The sweet spot for regular users. Everything in Free, plus:

• ~160 GPT-5 messages every 3 hours
• 3,000 GPT-5-Thinking messages per week
• 50 o3 messages per week — Advanced reasoning model
• 25 Deep Research queries/month
• GPT-4o image generation — Native image creation with excellent text rendering
• Advanced Voice Mode — Real-time conversation with GPT-4o
• Custom GPTs — Build and share specialised chatbots
• Projects — Organise chats and files into workspaces
• Connectors — Gmail, Google Calendar, Dropbox, GitHub integration

Worth it for: Regular users who hit free tier limits, anyone wanting image generation, people who value voice conversations, professionals organising work into projects.

Subscribe to Plus →

Pro — $200/month

For power users and professionals who need maximum capability. Everything in Plus, plus:

• Near-unlimited GPT-5 and o3 — No practical limits for most users
• GPT-5 Thinking Pro mode — Extended reasoning with more compute
• 256K token context window — Double the standard context
• 250 Deep Research queries/month — 10× the Plus allocation
• Sora video generation — Create videos from text prompts
• Priority compute — Faster responses during high demand
• ChatGPT Pulse — Proactive insights and recommendations
• Custom connectors via MCP — Build your own integrations

Worth it for: Researchers, consultants, writers, developers, and anyone whose work depends heavily on AI. The cost is justified if you’re using ChatGPT professionally for several hours daily.

Introduced December 2024 →

Business — $25–30/user/month

Formerly called “Team” (renamed August 2025). Designed for organisations:

• Unlimited GPT-5 (fair use policy)
• GPT-5 Thinking Pro mode
• Admin dashboard — User management, usage analytics
• Data excluded from training — Your conversations are never used to train models
• SAML SSO — Enterprise authentication
• Shared workspaces — Collaborate on projects across team members
• Priority support

Minimum 2 users. Annual billing available at reduced rates.

Learn more about Business →

Enterprise — Custom pricing

For large organisations requiring maximum security and customisation. Estimated ~$60/user/month based on public reports:

• 2 million token context window — Handle massive documents
• Custom data retention policies
• SOC 2 Type 2 compliant
• Enterprise Key Management (EKM) — Customer-controlled encryption keys
• SCIM provisioning — Automated user management
• Data residency options — US, Europe, UK, Japan, Canada, South Korea, Singapore, Australia, India, UAE
• Dedicated support and onboarding

92% of Fortune 500 companies now use ChatGPT Enterprise.

Contact sales →

Models powering ChatGPT

ChatGPT’s model architecture consolidated significantly in 2025. Here’s what’s currently available:

GPT-5.1 (November 2025)

The latest flagship model, described as “warmer, more intelligent” with an updated conversational style. Users select between three modes:

• Auto — Model intelligently chooses the optimal approach
• Fast — Prioritises speed for quick responses
• Thinking — Extended reasoning for complex problems (uses more of your quota)

GPT-5.1 replaced GPT-5 (August 2025), which itself unified GPT-4o, o3, o4-mini, GPT-4.1, and GPT-4.5 into a single model.

o3 and o4-mini (April 2025)

OpenAI’s reasoning models excel at mathematics, science, coding, and visual perception. o3 is the heavyweight for complex problems; o4-mini provides faster, more cost-efficient reasoning. Available to Plus and Pro users.

GPT-5.1-Codex-Max (November 2025)

A specialised variant for long-running, project-scale coding work. Handles tasks that take 24+ hours, maintaining context across extensive codebases. Pro tier only.

Legacy models

• GPT-4o — Still available, marked as legacy
• GPT-4.1 — Offers 1 million token context for specific use cases
• GPT-4o mini — Powers unlimited free tier usage

Open-weight models

In August 2025, OpenAI released gpt-oss-120b and gpt-oss-20b under Apache 2.0 license—their first open-source models.

Features deep dive

Web browsing and ChatGPT Search

ChatGPT Search became available to all users (including logged-out visitors) on 5 February 2025. Built on a fine-tuned GPT-4o with Bing API integration and news partnerships (AP, Reuters, Financial Times), it provides:

• Inline citations with hover-to-preview functionality
• Rich visual results for weather, stocks, sports, maps
• Automatic triggering when queries benefit from current information
• Source transparency — See exactly where information comes from

The feature competes directly with Google and Perplexity, offering conversational search that synthesises information rather than just listing links.

Deep Research

Deep Research operates as an agentic feature that independently discovers, reasons about, and consolidates insights across the web. Unlike simple browsing, it:

• Autonomously navigates dozens of sources
• Cross-references and fact-checks information
• Produces comprehensive reports with citations
• Takes 5–30 minutes depending on complexity

Monthly limits: Pro gets 250 queries, Plus/Business/Enterprise get 25, Free gets 5.

A July 2025 update added visual browser capabilities—the agent can click, scroll, and navigate websites, pausing at login pages for user confirmation.

Advanced Voice Mode

Advanced Voice Mode uses GPT-4o’s native multimodal processing—speech is understood directly rather than converted through text intermediaries. This enables:

• Sub-3-second response times
• Emotional recognition — Detects tone and responds appropriately
• Natural conversation flow — Varied pitch, subtle emphasis, interruption handling
• 9 distinct voices — Plus a seasonal “Santa” voice in December 2025
• Camera and screen sharing — Show ChatGPT what you’re looking at during voice chat

As of November 2025, voice mode integrates directly into the chat interface (no separate full-screen required), allowing users to talk while viewing live transcripts and rich content.

Availability:

• Free users: GPT-4o mini voice with daily limits
• Plus/Business users: GPT-4o voice until daily minutes exhaust, then GPT-4o mini
• Pro users: Unlimited GPT-4o voice

Image generation with GPT-4o

GPT-4o native image generation (internally called “GPT Image 1”) replaced DALL-E 3 as the default on 25 March 2025. This represents a fundamental shift—images are now generated as part of GPT-4o itself rather than calling a separate tool.

Key improvements over DALL-E 3:

• Dramatically better text rendering — Legible text in images, finally
• Precise specifications — Aspect ratios, hex colours, transparent backgrounds
• Selection tool — Highlight specific areas for targeted edits
• Coherent style — Better consistency across generated images

Generation takes up to one minute due to detail level. DALL-E 3 remains available as a legacy option through a dedicated GPT in the GPT Store.

Available to: Plus, Pro, Business, Enterprise users.

Code execution (Advanced Data Analysis)

The code interpreter runs Python in a sandboxed environment with 300+ pre-installed libraries including pandas, numpy, matplotlib, scikit-learn, scipy, and more.

Capabilities:

• Data analysis and visualisation
• File format conversion
• Statistical analysis
• Chart and graph generation
• PDF manipulation
• Image processing

Limitations:

• 120-second runtime limit per execution
• No internet access from the sandbox
• State clears when the environment dies
• Some libraries unavailable for security reasons

File uploads and handling

ChatGPT supports extensive file upload capabilities:

Supported formats: PDF, DOCX, XLSX, CSV, TXT, PNG, JPEG, GIF, WebP, code files (Python, JavaScript, etc.)

Size limits:

• Documents: Up to 512MB per file
• Images: Up to 20MB
• Text content: Up to 2 million tokens (~500,000 words)

Upload limits:

• Plus users: 80 files every 3 hours
• Free users: 3 files daily

Storage caps:

• Individual: 10GB
• Organisation: 100GB

Memory and personalisation

ChatGPT’s memory system has two components:

1. Saved Memories — Explicitly requested or automatically captured details about you
2. Reference Chat History — Rolled out April 2025 for Plus/Pro, June 2025 for Free

This enables ChatGPT to remember your preferences, communication style, interests, and context across conversations. It’s a unique differentiator—neither Claude nor Gemini offers persistent memory.

Managing memory:

• View: Ask “What do you remember about me?”
• Control: Settings > Personalization > Manage Memories
• Delete: Remove individual memories or clear all
• Notifications: You’re informed when memories are added

Temporary Chat provides incognito mode—conversations aren’t saved to history, aren’t used for training, and don’t update memory. Data deleted within 30 days.

Custom GPTs and the GPT Store

Over 3 million Custom GPTs have been created through OpenAI’s no-code builder. To create one:

1. Describe the desired functionality in natural language
2. Upload knowledge files (up to 20)
3. Configure custom actions for API integration
4. Set conversation starters and personality

The GPT Store marketplace serves Plus, Business, and Enterprise users with featured and trending categories across productivity, writing, research, programming, education, and lifestyle.

Monetisation: A revenue-sharing program based on engagement metrics exists for US-based creators, though implementation details remain sparse. Most creators monetise through affiliate marketing, external paywalls, or consulting services.

Canvas for collaborative editing

Canvas provides a dedicated two-pane workspace for writing and coding projects. The feature auto-triggers when ChatGPT detects content exceeding 10 lines or editing scenarios.

Writing shortcuts:

• Adjust length (shorter/longer)
• Change reading level (from 5th grade to graduate)
• Add final polish
• Add emojis
• Translate

Coding shortcuts:

• Review code
• Add logging/comments
• Fix bugs
• Port to other languages (JavaScript, Python, Java, C++, PHP, TypeScript)
• Run code

Key capabilities:

• Inline highlighting for targeted edits
• Version history with “show changes” highlighting
• Export to PDF, Markdown, Word, or language-specific code files

Available on web, Windows, and macOS. Mobile support coming soon.

Projects for organised workspaces

Projects group related chats and files into dedicated workspaces with persistent context. Originally launched December 2024 for paid tiers, expanded to Free users in 2025 with limitations.

Each project supports:

• Custom instructions specific to that project
• Up to 20 file uploads (40 for Pro users)
• Memory that persists across all project chats
• Colour coding and organisation

Shared Projects (October 2025) allow multiple people to participate—members can start chats and view others’ sessions.

Connectors

Connectors provide direct integration with external tools:

• Google: Gmail, Calendar, Drive
• Microsoft: Outlook, Teams, SharePoint, OneDrive
• Development: GitHub
• Storage: Dropbox, Box
• CRM: HubSpot

This allows ChatGPT to search your emails, check your calendar, find documents, and take actions—all through natural conversation.

Note: Connectors are unavailable in EEA, Switzerland, and UK due to regulatory constraints.

Pro users can build custom connectors via MCP (Model Context Protocol).

Tasks and scheduling

Tasks (launched January 2025) enable one-time or recurring prompts:

• Daily news briefings on topics you care about
• Stock price updates at market open
• Language learning exercises each morning
• Weather reports before your commute
• Weekly report summaries

You can maintain up to 10 active tasks, receiving push and email notifications upon completion.

Video generation with Sora

Pro users gain access to Sora, OpenAI’s video generation model. Create videos from text prompts, with controls for style, duration, and content. Still in early access with usage limits.

Strengths

Market dominance — 800M weekly users and 79–81% market share means the largest ecosystem, most third-party integrations, and most community resources.

All-in-one platform — Text, images, voice, video, code, research, browsing—no competitor offers this breadth in a single interface.

Persistent memory — The only major AI assistant that remembers you across conversations. Neither Claude nor Gemini has this.

Voice mode quality — Advanced Voice Mode is genuinely impressive. Real-time conversation that feels natural, with emotional intelligence and sub-3-second responses.

Ecosystem depth — 3M+ Custom GPTs, 1,000+ third-party integrations, extensive documentation, massive community.

Free tier generosity — Access to GPT-5, web browsing, Deep Research, and voice mode at no cost. More capable than many paid competitors.

Enterprise maturity — SOC 2, ISO certifications, data residency options, EKM encryption. 92% of Fortune 500 companies trust it.

Limitations

Rate limits frustrate power users — Even on Plus, you can hit GPT-5 limits during heavy use. Pro’s $200/month is steep for individuals.

Context window constraints — 128K tokens (256K on Pro) falls behind Claude’s 200K and Gemini’s 1M+. Matters for long documents.

Coding isn’t best-in-class — Claude scores higher on SWE-bench (72.5% vs ChatGPT’s lower scores). For dedicated coding work, specialised tools like Cursor may be better.

Peak-time slowdowns — Free tier especially can be slow during high-demand periods.

Privacy complexity — Default data usage for training (on Free/Plus) requires opt-out. Enterprise privacy features cost significantly more.

Connector restrictions — EEA/UK users can’t access many integration features due to regulation.

Video generation limits — Sora access is Pro-only and still constrained by usage caps.

Who should use ChatGPT?

Great for:

• General AI users — If you want one AI assistant for everything, ChatGPT’s breadth is unmatched
• Visual creators — GPT-4o image generation produces excellent results with readable text
• Voice-first users — Advanced Voice Mode is the best in the industry
• Builders — Custom GPTs let you create specialised tools without coding
• Researchers — Deep Research and web browsing provide powerful information synthesis
• Enterprise teams — Mature security, compliance, and admin features

Look elsewhere if:

• Maximum context is essential — Gemini offers 1M+ tokens vs ChatGPT’s 128K–256K
• Deep coding is your primary use — Claude or Cursor may serve you better
• Privacy is paramount — Claude’s approach may suit you better (no training on conversations by default)
• Google ecosystem integration — Gemini’s native Workspace integration is seamless
• Budget is extremely tight — Free tier is good, but Claude and Gemini free tiers may suit specific needs better

Historical timeline

Privacy and data handling

Understanding how OpenAI handles your data is crucial. Here’s the breakdown:

Training data policy

To opt out: Settings > Data Controls > “Improve the model for everyone” → Off

Temporary Chat

Temporary Chat provides incognito mode:

• Conversations aren’t saved to your history
• Not used for model training
• Don’t update your memory
• Retained for 30 days for safety monitoring only, then deleted

Data retention

• Regular chats: Retained until you delete them
• Deleted content: Removed from systems within 30 days
• Temporary chats: 30 days maximum, safety monitoring only

Security certifications

Enterprise and Business products hold:

• SOC 2 Type 2 — Security, availability, processing integrity
• ISO 27001 — Information security management
• ISO 27017 — Cloud security
• ISO 27018 — Protection of personal data in cloud
• ISO 27701 — Privacy information management

Visit OpenAI’s Trust Portal for audit reports and compliance documentation.

Data residency

Enterprise customers can choose data residency in: US, Europe, UK, Japan, Canada, South Korea, Singapore, Australia, India, UAE.

Enterprise Key Management (EKM)

Enterprise tier supports customer-controlled encryption keys—your data is encrypted with keys you control, providing an additional security layer.

ChatGPT vs alternatives

Quick comparison

Where ChatGPT wins

• Persistent memory — Only ChatGPT remembers you across conversations
• Ecosystem size — 3M+ Custom GPTs, 1,000+ integrations
• Voice quality — Most natural, responsive voice mode
• All-in-one breadth — Text, images, video, voice, code, research in one place

Where competitors win

• Claude — Better coding (72.5% SWE-bench), superior long-form writing, stronger safety
• Gemini — Larger context (1M+ tokens), native Google integration, aggressive API pricing, video generation

Getting started

Web

1. Go to chatgpt.com
2. Sign up with email, Google, Microsoft, or Apple
3. Start chatting—no setup required

Mobile

• iOS: Download from App Store
• Android: Download from Google Play

Desktop

Download from openai.com/chatgpt/download:

• macOS: Requires Apple Silicon, macOS 14+
• Windows: Windows 10 or 11

Tips for new users

Be specific: “Write a professional email declining a meeting due to a schedule conflict” beats “write an email.”

Use follow-ups: ChatGPT maintains context. Ask for revisions, clarifications, or different approaches.

Try voice mode: Tap the headphone icon for hands-free conversation. Great for brainstorming or when you can’t type.

Explore the GPT Store: Thousands of specialised GPTs for writing, coding, research, image generation, and more.

Set up memory: Tell ChatGPT about yourself—job, preferences, communication style—and it’ll remember across conversations.

FAQs

Is ChatGPT free?

Yes. The free tier includes GPT-4o mini (unlimited), limited GPT-5 access, web browsing, voice mode, and 5 Deep Research queries monthly. Genuinely useful, not just a demo.

Is ChatGPT Plus worth $20/month?

If you hit free tier limits regularly, want image generation, or value Advanced Voice Mode—yes. The 160 GPT-5 messages/3 hours and Custom GPTs creation make it worthwhile for regular users.

What about the $200 Pro tier?

Only for power users who need near-unlimited access, video generation via Sora, or extended reasoning capabilities. Most people are well-served by Plus.

Can ChatGPT access the internet?

Yes. All tiers can browse the web for current information. Deep Research goes further, autonomously exploring dozens of sources to compile comprehensive reports.

Is my data private?

Free and Plus conversations may be used for training by default—opt out in Settings > Data Controls. Business and Enterprise conversations are never used for training.

What’s the difference between GPT-5 and GPT-5.1?

GPT-5.1 (November 2025) is described as “warmer, more intelligent” with an updated conversational style. It’s an incremental improvement over GPT-5 (August 2025), which unified previous models.

Can ChatGPT generate images?

Yes, on paid tiers. GPT-4o native image generation produces high-quality images with readable text—a significant improvement over DALL-E 3.

Does ChatGPT remember previous conversations?

Yes. The memory feature stores details about you across conversations. You can view, manage, and delete memories in Settings > Personalization. Use Temporary Chat for private conversations that aren’t remembered.

What file types can I upload?

PDF, DOCX, XLSX, CSV, TXT, PNG, JPEG, GIF, WebP, and various code files. Up to 512MB per document file, 20MB per image. Free users limited to 3 uploads daily.

Verdict

ChatGPT earned its position as the world’s most popular AI assistant through relentless iteration and feature expansion. The combination of GPT-5.1’s intelligence, Advanced Voice Mode’s naturalness, native image generation, Deep Research’s thoroughness, and persistent memory creates an all-in-one platform that no competitor fully matches.

Free tier: Genuinely useful for casual use. The GPT-4o mini unlimited access, web browsing, and limited GPT-5 make it the best free AI assistant available.

Plus ($20/month): The sweet spot for most users. Image generation, full voice mode, Custom GPTs, Projects, and Connectors justify the cost for regular users.

Pro ($200/month): Only for power users whose work depends on AI. The near-unlimited access, extended reasoning, and Sora video generation serve researchers, consultants, and professionals who use ChatGPT for hours daily.

ChatGPT isn’t the best at everything—Claude writes better long-form content and scores higher on coding benchmarks, Gemini offers vastly longer context windows—but it’s very good at everything, and it’s the only major assistant with persistent memory. For most people wanting a single, capable AI assistant, ChatGPT remains the default choice.

Official links