The Big Comparison Table
| Feature | Claude Opus 4.6 | Claude Sonnet 4.5 | Claude Haiku 4.5 | GPT-4o | o3 | Grok-3 |
|---|---|---|---|---|---|---|
| Code Quality | Best | Excellent | Good | Very Good | Excellent | Good |
| Speed | Moderate | Fast | Fastest | Fast | Slow | Fast |
| Context Window | 200K | 200K | 200K | 128K | 200K | 128K |
| Input Cost / 1M | $15 | $3 | $0.80 | $2.50 | $10 | Varies |
| Output Cost / 1M | $75 | $15 | $4 | $10 | $40 | Varies |
| Instruction Following | Best | Excellent | Good | Good | Very Good | Fair |
| Debugging | Best | Very Good | Fair | Very Good | Excellent | Good |
| Agentic / CLI | Claude Code | Claude Code | Limited | Copilot | Limited | None |
| Real-time Data | No | No | No | With browsing | With browsing | Yes (X/Twitter) |
| Image Input | Yes | Yes | Yes | Best | Yes | Yes |
Recommendations by Use Case
Best for Complex Projects
Claude Opus 4.6 — When you're building a multi-file application with complex business logic, database schemas, and authentication. Opus follows intricate instructions precisely and generates architecturally sound code.
Best for Daily Vibe Coding
Claude Sonnet 4.5 — The everyday workhorse. Fast enough for rapid iteration, smart enough for most coding tasks, and affordable enough that you won't worry about your bill.
Best for Beginners
ChatGPT (GPT-4o) — The most familiar interface, biggest community for help, and works well with the free tier. Great for learning the vibe coding workflow.
Best for Budget Coding
Claude Haiku 4.5 — At under $1 per million input tokens, Haiku is the cheapest capable model. Use it for autocomplete, simple scripts, and utility functions.
Best for Hard Reasoning Problems
o3 (OpenAI) — When you have an algorithmic puzzle, complex data transformation, or tricky optimization problem, o3's reasoning capabilities shine.
Best for Cutting-Edge Info
Grok-3 — When you need the latest framework versions, just-released APIs, or current best practices, Grok's real-time data access helps.
The Bottom Line
If you're just starting: Use ChatGPT (free) or Claude Sonnet on claude.ai (free tier available).
If you want the best code: Use Claude Opus 4.6 or Claude Sonnet 4.5 in Cursor or Claude Code.
If you want it all: Use Sonnet 4.5 for everyday coding, switch to Opus for hard problems, and keep Haiku for autocomplete. This combo gives you the best of all worlds.