OpenAI: GPT-5 Codex

Claude is Anthropic's family of AI assistants, known for long-context reasoning, careful writing and strong coding ability. The Opus, Sonnet and Haiku tiers let you trade off intelligence, speed and cost. Claude excels at nuanced analysis, document understanding and agentic coding workflows, and is a favourite among developers and writers who value clarity.

ChatGPT is OpenAI's flagship conversational AI, powering hundreds of millions of weekly users across web, mobile and API. Built on the GPT-4o and GPT-5 family of models, it handles text, images, voice and code in a single interface. With browsing, data analysis, custom GPTs and a vast plugin ecosystem, it remains the default assistant for most knowledge workers.

Gemini is Google's natively multimodal model family, deeply integrated across Search, Workspace, Android and the Pixel line. Its standout feature is an enormous context window of up to one to two million tokens, ideal for analysing long videos, codebases and document sets. Gemini blends Google's real-time knowledge with strong reasoning and is available free in many products.

Cursor is an AI-first code editor, a fork of VS Code rebuilt around deep model integration. Its agent mode can plan and execute multi-file changes, while features like Tab completion, codebase-wide context and inline edits make it feel like the editor and AI are one. Cursor has become a favourite among developers building with AI at the centre of their workflow.

DeepSeek is a Chinese AI lab that stunned the industry with frontier-level reasoning models at a fraction of typical costs. Its R-series reasoning models and V-series chat models are open-weight and extremely cheap via API. DeepSeek is the go-to choice for developers who need strong math, coding and reasoning performance on a tight budget.