Which is better for coding, Claude Opus 5 or GPT-5.6 Sol?

It's close. Claude Opus 5 leads SWE-bench Verified at 96.0% and edges FrontierCode 1.1 (53.4% vs 47.5%). GPT-5.6 Sol leads the Artificial Analysis Coding Agent Index (~80) and Terminal-Bench 2.1 (88.8%, 91.9% in Ultra mode). Opus 5 wins static repo edits; Sol wins long agentic terminal runs.

How much do Claude Opus 5 and GPT-5.6 Sol cost?

Claude Opus 5 is $5/$25 per million input/output tokens (launched July 24, 2026). GPT-5.6 Sol is $5/$30, so its output tokens cost 20% more. Sol Ultra jumps to $12.50/$75. On a 30K-in/5K-out task, Opus 5 runs about $0.28 vs $0.30 for Sol.

Which has the bigger context window?

GPT-5.6 Sol has a slightly larger context window at 1.05M tokens versus Claude Opus 5's 1M. Both are large enough for most multi-file repos; the difference rarely matters in practice.

Quick Answer

Claude Opus 5 vs GPT-5.6 Sol: Coding Winner (July 2026)

Published: July 31, 2026

The Short Answer

Claude Opus 5 and GPT-5.6 Sol are a near-tie for coding in July 2026. Opus 5 leads on SWE-bench Verified (96.0%) and static repo edits; GPT-5.6 Sol leads the Artificial Analysis Coding Agent Index and long-horizon terminal agents. Pick Opus 5 for accuracy-critical refactors, Sol for autonomous agentic runs.

Benchmarks Head-to-Head

	Claude Opus 5	GPT-5.6 Sol
Launched	Jul 24, 2026	Jul 9, 2026 (GA)
SWE-bench Verified	96.0%	not published
Terminal-Bench 2.1	—	88.8% (91.9% Ultra)
AA Coding Agent Index	~78	~80 (leads)
FrontierCode 1.1	53.4%	47.5%
Context	1M	1.05M
Price ($/MTok)	$5 / $25	$5 / $30

Opus 5 posts the single highest SWE-bench Verified score at 96.0% and wins FrontierCode 1.1 head-to-head (53.4% vs 47.5%). GPT-5.6 Sol tops the Artificial Analysis Coding Agent Index (~80) — which weights DeepSWE, Terminal-Bench v2, and SWE-Atlas-QnA — making it the stronger long-agentic-run model.

Where Each Wins

Claude Opus 5 → accuracy-critical work. The 96.0% SWE-bench Verified score and FrontierCode lead make it the safer pick for hard multi-repo refactors where a wrong edit is expensive.
GPT-5.6 Sol → autonomous terminal agents. Its Coding Agent Index lead and 88.8% Terminal-Bench 2.1 (91.9% in Ultra mode) point to stronger long-horizon, tool-using agent loops.

The Price Angle

Both cost $5 per million input tokens, but Opus 5’s output is $25 vs Sol’s $30 — a 20% edge to Anthropic on the tokens that dominate agentic cost. On a 30K-in/5K-out task, Opus 5 runs about $0.28 vs $0.30 for Sol. Sol Ultra ($12.50/$75) is far pricier and only worth it for the hardest steps.

Verdict

For most teams: Opus 5 as the default coder, Sol for autonomous agent loops. If you’re routing by cost, both sit in the same $5-input tier — decide on output price ($25 vs $30) and which benchmark matches your workload.

Sources

Anthropic — Claude Opus 5: anthropic.com/news/claude-opus-5
OpenAI — GPT-5.6: openai.com/index/gpt-5-6
Artificial Analysis — Coding Agent Index: artificialanalysis.ai