o3 alternatives
Looking for an alternative to o3? Here are the 6 closest llm provider / model options for AI coding, each ranked by how well it replaces o3 — with the concrete reason to switch.
Quick comparison
| Model | Input price | SWE-bench | Context window | Speed |
|---|---|---|---|---|
| o3 (you) | $10 | 71% | 200K | Slow/Reasoning |
| Claude Opus 4.7 | $15 | 72% | 200K | Slow/Reasoning |
| GPT-5.5 | $5 | 75% | 1M+ | Standard |
| GPT-5.5 Pro | $30 | 78% | 1M+ | Slow/Reasoning |
| MiMo V2.5 Pro | Free (self-hosted) | 79% | 1M+ | Standard |
| DeepSeek V4 Pro | $0.44 | 62% | 1M+ | Slow/Reasoning |
| Gemini 2.5 Pro | $1.25 | 63% | 1M+ | Standard |
The best o3 alternatives
Complex refactors, agentic coding, hard debugging, deep reasoning
Why consider it instead:
- Higher SWE-bench (72% vs 71%)
GPT-5.5
Frontier reasoning, agentic coding, long-context refactors, multimodal analysis, replaces GPT-5.4 as default flagship
Why consider it instead:
- Cheaper — $5/1M input vs $10, ~2.0× less
- Higher SWE-bench (75% vs 71%)
- Bigger context window (1M+)
Hardest reasoning problems, math olympiad, research-grade analysis, mission-critical coding tasks where cost is no object
Why consider it instead:
- Higher SWE-bench (78% vs 71%)
- Bigger context window (1M+)
Highest open-weight coding performance, 1M context agentic tasks, complex multi-step engineering, long-context reasoning
Why consider it instead:
- Cheaper — $0/1M input vs $10
- Higher SWE-bench (79% vs 71%)
- Bigger context window (1M+)
Complex reasoning, agentic coding, hard debugging with long context
Why consider it instead:
- Cheaper — $0.44/1M input vs $10, ~22.7× less
- Bigger context window (1M+)
Advanced reasoning, multimodal workflows, massive context tasks, agentic coding
Why consider it instead:
- Cheaper — $1.25/1M input vs $10, ~8.0× less
- Bigger context window (1M+)
Switching from o3? Check the new tool fits the rest of your stack — Flowpicker shows compatibility warnings live.
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