How much do Claude Opus 5, GPT-5.6 Sol, and Grok 4.6 cost?

Claude Opus 5 is $5 input / $25 output per million tokens. GPT-5.6 Sol is $5 / $30 (Sol Ultra is $12.50 / $75). Grok 4.6 has no official price as of August 11, 2026 but shares Grok 4.5's foundation and is expected to hold $2 / $6 — about 2.5x cheaper than the other two.

Is Grok 4.6 as good as Claude Opus 5?

No — as of August 2026 Claude Opus 5 leads on raw coding and agentic quality, and xAI has not published official Grok 4.6 benchmarks. Grok 4.6 improves on Grok 4.5's hallucinations and instruction-following via better fine-tuning, but its edge is price and token efficiency, not top-of-leaderboard accuracy.

Quick Answer

Claude Opus 5 vs GPT-5.6 Sol vs Grok 4.6 (Aug 2026)

Q: Which frontier AI model is best in August 2026?

As of August 2026, Claude Opus 5 leads the Artificial Analysis Intelligence Index (61) and the Agentic Index (55.3) at $5/$25 per MTok — best for coding and agentic quality. GPT-5.6 Sol is competitive and wins specific evals at $5/$30. Grok 4.6 (launched Aug 7) is the cheapest at Grok 4.5's $2/$6, best for cost-sensitive high volume. Pick Opus 5 for quality, GPT-5.6 Sol for reasoning breadth, Grok 4.6 for price.

Published: August 11, 2026

The Short Answer

As of August 2026, Claude Opus 5 leads on coding and agentic quality (Intelligence Index 61, Agentic Index 55.3) at $5/$25. GPT-5.6 Sol is competitive and wins specific evals at $5/$30. Grok 4.6 (launched Aug 7) is the cheapest at Grok 4.5’s $2/$6. Pick by quality, reasoning breadth, or price.

Quick Comparison

	Claude Opus 5	GPT-5.6 Sol	Grok 4.6
Vendor	Anthropic	OpenAI	xAI
Price (in/out per MTok)	$5 / $25	$5 / $30	~$2 / $6 (expected)
Intelligence Index	61 (leads)	59 (max effort)	TBD (no official card)
Context	1M	1M	Large
Best for	Coding + agents	Reasoning breadth	Cost-sensitive volume

Claude Opus 5 — Quality Leader

Opus 5 (July 24, 2026) tops the Intelligence Index (61) and Agentic Index (55.3) at the same $5/$25 as Opus 4.8 — 1M context, 128K max output, now the default Opus. Independent build tests repeatedly pick it as the best of the frontier three for detailed, keep-working-on-it output. The pick for coding and long-horizon agents.

GPT-5.6 Sol — Reasoning Breadth

GPT-5.6 Sol scores 59 at max effort and wins on a handful of specific evaluations. It’s $5/$30 ($30 output makes it the priciest per output token here), with Sol Ultra at $12.50/$75 for hardest problems and 1M context. Strong all-rounder; best where OpenAI’s ecosystem and reasoning breadth matter.

Grok 4.6 — Cheapest Frontier

Grok 4.6 (August 7, 2026) reuses Grok 4.5’s 1.5T foundation with upgraded SFT/RL targeting hallucinations and instruction-following. Expected to hold Grok 4.5’s $2/$6 — ~2.5x cheaper than Opus 5 or Sol — with high token efficiency. No official benchmarks yet, so it’s the value pick, not the accuracy pick.

Which Should You Pick?

Best coding + agentic quality → Claude Opus 5.
Reasoning breadth / OpenAI stack → GPT-5.6 Sol.
Cheapest frontier for high volume → Grok 4.6.

The Reality Check

The quality gap between these three is narrower than the price gap. If your workload is mostly routine, Grok 4.6 at ~$2/$6 saves real money; reserve Opus 5 and Sol Ultra for the hardest agentic and reasoning tasks where quality pays for itself.

Sources

Orbilon Tech — Opus 5 leads Intelligence Index 61 / Agentic 55.3: orbilontech.com
Kie.ai — Grok 4.6 (launched Aug 7, 2026, 1.5T V9): kie.ai
Anthropic — Claude pricing/models: anthropic.com