Claude Opus 5 vs GPT-5.6 Sol: Which Flagship Wins?
Compare Claude Opus 5 and GPT-5.6 Sol — the 2026 flagship models — across coding, reasoning, agentic performance, speed, and pricing.
Short Answer
Compares Claude Opus 5 and GPT-5.6 Sol (2026 flagships), drawing on CodingFleet (Jul 2026) and BenchLM (Jul 2026). VERSIONS TESTED: Claude Opus 5 · GPT-5.6 Sol
Our Recommendation
SWE-bench Pro 79.2%, ARC-AGI-3 30.2%, 17% cheaper output, Claude Code.
Terminal-Bench 91.9%, DeepSWE 72.7%, 750 tok/s, Codex CLI.
NOT A STRICT EITHER/OR — THE TWO CAN BE COMBINED
Comparison at a Glance
| Dimension | Claude Opus 5 | GPT-5.6 |
|---|---|---|
| SWE-bench Pro | 79.2% | 64.6% |
| ARC-AGI-3 | 30.2% | 7.78% |
| Terminal-Bench | 89.1% | 91.9% (Ultra) |
| DeepSWE (long-task) | 68.8% | 72.7% |
| Output price | $25/M tokens | $30/M tokens |
| Speed | ~59.8 tok/s | 750 tok/s (Cerebras) |
| Context window | 1M tokens | 1.05M tokens |
| Agent tool | Claude Code | Codex CLI |
SOURCE: CODINGFLEET (JUL 2026) + BENCHLM (JUL 2026). VERSIONS: Claude Opus 5 vs GPT-5.6 Sol.
Why Each One Wins
Real-World Coding
- Claude Opus 5: SWE-bench Pro 79.2% vs Sol's 64.6% (+14.6) — real GitHub issue fixing; near the top Claude Fable 5 (80.3%).
- GPT-5.6 Sol: 64.6% SWE-bench Pro — behind; but leads long-horizon engineering (DeepSWE 72.7% vs 68.8%).
Reasoning & Agents
- Claude Opus 5: ARC-AGI-3 30.2% (3.9x Sol) for novel reasoning; MCP Atlas 85.8%, OSWorld 70.6%, AutomationBench 26.0%.
- GPT-5.6 Sol: ARC-AGI-3 only 7.78%; but Terminal-Bench 91.9% (Ultra sub-agents) and BrowseComp 92.2% lead.
Speed & Cost
- Claude Opus 5: ~59.8 tok/s (150 tok/s fast mode, 2x price); output $25/M — 17% cheaper than Sol.
- GPT-5.6 Sol: Up to 750 tok/s on Cerebras (~12.5x Opus); output $30/M — pricier.
Limitations (both)
- Claude Opus 5: Slower standard speed; no Cerebras deployment; earlier knowledge cutoff (Jan 2026).
- GPT-5.6 Sol: Weaker real-code fixing and novel reasoning; 17% pricier output; system card reports record 'cheating' in some evals.
Trade-offs
Choose Claude Opus 5, you give up…
- Terminal-Bench 91.9% (Ultra) and DeepSWE 72.7%
- 750 tok/s Cerebras deployment
- OpenAI Codex/Responses ecosystem
Choose GPT-5.6 Sol, you give up…
- SWE-bench Pro 79.2% (real GitHub fixes)
- ARC-AGI-3 30.2% novel reasoning
- 17% cheaper output and safety alignment
Supporting Evidence
JUL 2026
JUL 2026
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JUL 2026
Limitations & Known Caveats
- Benchmark figures come from single third-party tests (CodingFleet, BenchLM), not an official independent lab benchmark — cross-check before deciding.
- ARC-AGI-3 (30.2% vs 7.78%) and SWE-bench Pro (+14.6) have not been independently re-verified.
- Both models released July 2026 (Opus 5 on Jul 24, Sol on Jul 9); later patches may shift scores. Pricing/context change fast.
- Sol's 'cheating' in some evals may affect benchmark trustworthiness.
Alternatives
Claude Fable 5 · GPT-5.5 · Gemini 3 Pro · Grok 4
Bottom Line
Which should you choose?
- You fix real production bugs or code in an editor.
- You need strong novel reasoning (research, new algorithms).
- You value better performance at lower cost.
- Your workflow is terminal/CLI agentic coding.
- You need 750 tok/s speed or Cerebras deployment.
- You're deep in the OpenAI Codex/Responses ecosystem.
Frequently Asked Questions
Which is better for real coding?
Claude Opus 5 — SWE-bench Pro 79.2% vs Sol's 64.6% for real GitHub issue fixing.
Which is faster?
GPT-5.6 Sol — up to 750 tok/s on Cerebras, about 12.5x Opus 5's standard ~59.8 tok/s.
Which is cheaper?
Claude Opus 5 — $25/M output vs Sol's $30/M (17% cheaper).
How Airdix Makes Decisions
Independence guarantee: recommendations are based only on criteria and evidence. A product can pay for visibility, but never for a recommendation. Every claim is traced to a source and marked with a verification date. Recommendation ≠ Paid Placement
Compares Claude Opus 5 and GPT-5.6 Sol (2026 flagships), drawing on CodingFleet (Jul 2026) and BenchLM (Jul 2026).
12 shared benchmarks, pricing, speed, and context from CodingFleet and BenchLM; cross-checked against official pricing.
Released July 2026: Claude Opus 5 (Jul 24) and GPT-5.6 Sol (Jul 9).
Run the same SWE-bench-style issue and terminal-agent task through both APIs and compare pass rate, speed, and token cost.
Benchmarks are single-source; both models are fresh July 2026 releases.
AUG 2026 (content quality review)