Claude Sonnet 4.6 vs GPT-5.6
Pricing, benchmarks, and use case comparison
Quick take
- •Claude Sonnet 4.6 is meaningfully stronger at cost efficiency (84 vs 70 on our capability index).
- •GPT-5.6 is meaningfully stronger at math (92 vs 80).
- •Claude Sonnet 4.6 is 40% cheaper on input tokens, which compounds fast on high-volume or agentic workloads.
Specs comparison
| Claude Sonnet 4.6 | GPT-5.6 | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Type | Closed source | Closed source |
| Context window | ✓1M | Not announced |
| Input / 1M tokens | ✓$3.00 | 5 |
| Output / 1M tokens | $15.00 | 30 |
| Release date | 2026-02 | 2026-06 |
Benchmarks
| Benchmark | Claude Sonnet 4.6 | GPT-5.6 |
|---|---|---|
| SWE-bench Verified | 79.6% | - |
| Terminal-Bench 2.0 | 59.1% | - |
| OSWorld-Verified | 72.5% | - |
| GPQA | 79.7% | - |
| Terminal-Bench 2.1 (Sol) | - | 88.8% |
| Terminal-Bench 2.1 (Terra) | - | 82.5% |
| Terminal-Bench 2.1 (Luna) | - | 84.3% |
| Terminal-Bench 2.1 | - | 88.8 |
| 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 Sonnet 4.6 if...
- →You have an existing integration pinned to Sonnet 4.6 and want stability
- →You need a proven mid-tier model with 1M context at $3/$15
- →You want predictable behavior without the new-tokenizer/thinking changes in Sonnet 5
- →You are cost-sensitive and don't need Sonnet 5's incremental gains
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