Grok 4.5 vs Claude Sonnet 5: same price, shorter context, different ecosystem?

Grok 4.5 wins on output price and total per-call cost. Pick Sonnet 5 when you need >500K context, Anthropic's tool-calling ecosystem, or a deeper cache discount for highly-repetitive prompts.

Two mid-tier workhorses with identical input pricing and very different output prices.

Grok 4.5 and Claude Sonnet 5 sit at the same $2.00 per million input price, but diverge sharply on output ($6 vs $10) and context size (500K vs 1M). The choice for most buyers comes down to output volume and ecosystem lock-in.

By TechCompare · Updated

Cost Comparison

Based on 100,000 input tokens (50% cached), 5,000 output tokens, and 100 requests.

Option A
Grok 4.5
Wins 1 of 5 compared specs
Option B
Claude Sonnet 5
Wins 3 of 5 compared specs

Side-by-side specs

SpecGrok 4.5Claude Sonnet 5
Input Cost (per M)$2.00$2.00
Output Cost (per M)$6.00 (better on this spec)$10.00
Cached Input (per M)$0.30$0.20 (better on this spec)
Batch DiscountNo50% (better on this spec)
Context Window500K1M (better on this spec)

How they differ

Grok 4.5 is priced at $2.00 per million input tokens and $6.00 per million output tokens, with an 85% caching discount ($0.30 per million) and a 500K context window. Claude Sonnet 5 is priced at $2.00 per million input tokens and $10.00 per million output tokens, with a 90% caching discount ($0.20 per million) and a 1M context window plus Anthropic's mature tool-calling ecosystem. For a 100K input + 10K output request, Grok 4.5 costs $0.26 vs Sonnet 5's $0.30 - Grok is 40% cheaper on output and wins the call. Sonnet 5 counters with double the context window, deeper prompt-caching discount, and Anthropic's tooling maturity.

Verdict

Grok 4.5 wins on output price and total per-call cost. Pick Sonnet 5 when you need >500K context, Anthropic's tool-calling ecosystem, or a deeper cache discount for highly-repetitive prompts.

Which should you pick?

Choose Grok 4.5

Output-heavy workloads under 500K context where the lower per-call cost matters. Grok 4.5's $6/M output vs Sonnet 5's $10/M is real savings at scale.

Choose Claude Sonnet 5

Workloads above 500K context, agentic tasks relying on Anthropic's mature tool-calling, or repetitive prompts where Sonnet 5's 90% cache discount outweighs the output premium.

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