Claude Opus 4.8 vs GPT-5.6
Pricing, benchmarks, and use case comparison
Quick take
- •GPT-5.6 leads on 1 of 1 shared benchmarks, including Terminal-Bench 2.1 (88.8 vs 74.6%).
Specs comparison
| Claude Opus 4.8 | GPT-5.6 | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Type | Closed source | Closed source |
| Context window | ✓1M | Not announced |
| Input / 1M tokens | $5.00 | 5 |
| Output / 1M tokens | $25.00 | 30 |
| Release date | 2026-05 | 2026-06 |
Benchmarks
| Benchmark | Claude Opus 4.8 | GPT-5.6 |
|---|---|---|
| SWE-bench Verified | 88.6% | - |
| SWE-bench Pro | 69.2% | - |
| Terminal-Bench 2.1 | 74.6% | ✓88.8 |
| GPQA Diamond | 93.6% | - |
| Artificial Analysis Intelligence Index | 61.4 | - |
| Terminal-Bench 2.1 (Sol) | - | 88.8% |
| Terminal-Bench 2.1 (Terra) | - | 82.5% |
| Terminal-Bench 2.1 (Luna) | - | 84.3% |
| ExploitBench | - | Competitive with Anthropic Mythos Preview |
| ExploitGym | - | Significant improvements |
| GeneBench v1 | - | Not announced |
Scores sourced from official provider release posts and independent benchmark aggregators.
Which should you choose?
Choose Claude Opus 4.8 if...
- →You need top-tier autonomous coding and multi-step agentic reliability
- →You run long-horizon agent traces that previously derailed after compaction
- →You want enterprise-grade reasoning with 1M context and 128k output
- →You need throughput and are willing to pay fast-mode premium for 2.5x speed
Choose GPT-5.6 if...
- →You want to standardize on one model generation but route requests across cost/quality tiers
- →You are an approved preview partner exploring the newest OpenAI capabilities
- →Workloads spanning agentic coding, knowledge work, and research where tier flexibility helps