ChatGPT is the AI chat assistant built by OpenAI, and is one of the most widely used AI tools in the world. Available at chat.openai.com, it is powered by OpenAI’s GPT-4o model family and supports text, images, voice, file uploads, and a vast ecosystem of plugins and custom GPTs.
| Model | Context | Notes |
|---|
| GPT-4o | 128K tokens | Default — fast, multimodal, highly capable |
| GPT-4o mini | 128K tokens | Faster, cheaper, good for simple tasks |
| o1 / o1-pro | 128K tokens | Reasoning model — slow, deliberate, exceptional at maths and logic |
| o3 / o4-mini | 128K tokens | Latest reasoning models (2026) |
- Versatile — writing, coding, math, research, translation, summarisation
- Image understanding — paste screenshots or photos, ask questions about them
- Image generation — create images via DALL-E 3 (Plus plan)
- Voice conversations — natural real-time voice back-and-forth
- Custom GPTs — pre-built specialized assistants for specific tasks
- Plugins and web browsing — search the web, run code, analyse files
| Feature | Description |
|---|
| GPTs (Custom AI Agents) | Community-built specialized ChatGPT versions (e.g., PDF Analyzer, Coding Tutor) |
| Canvas | Collaborative writing and code editor inside ChatGPT |
| DALL-E 3 | Generate images from text prompts |
| Code Interpreter | Run Python code, analyze CSVs, create charts |
| Web Browsing | Search the internet in real time |
| File Uploads | PDFs, Word docs, images, spreadsheets |
| Voice Mode | Real-time audio conversation |
| Memory | Remember information across conversations |
| Plan | Price | Key Features |
|---|
| Free | $0 | GPT-4o mini, limited GPT-4o, basic features |
| Plus | $20/month | GPT-4o, DALL-E 3, web browsing, custom GPTs, more |
| Pro | $200/month | o1-pro, unlimited usage, advanced voice |
| Team | $25/user/month | Shared workspace, admin controls |
| Enterprise | Custom | SSO, audit logs, longer context |
ChatGPT is excellent for coding tasks:
- Write functions from natural language descriptions
- Explain what code does in plain English
- Debug errors — paste the error and code
- Refactor and optimize code
- Generate unit tests
- Translate code between languages
For a terminal-based coding agent from OpenAI, see OpenAI Codex CLI.
| Feature | ChatGPT | Claude | Gemini |
|---|
| Context | 128K | 200K | Up to 2M |
| Image generation | Yes (DALL-E) | No | Yes (Imagen) |
| Plugin ecosystem | Large (GPTs) | Limited | Growing (Gems) |
| Code interpreter | Yes | No | Yes |
| Voice mode | Yes | Yes | Yes |
| Web browsing | Yes | Yes (Pro) | Yes |
| Reasoning model | o1, o3, o4 | Claude Thinking | Gemini Thinking |