Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | Claude Sonnet 5 (Adaptive Reasoning, Xhigh Effort) | Gemini 2.5 Pro |
|---|---|---|
| Input ($/M tokens) | $2 | $1.25 |
| Output ($/M tokens) | $10 | $10 |
Verdict. Claude Sonnet 5 (Adaptive Reasoning, Xhigh Effort) and Gemini 2.5 Pro split the benchmark comparison evenly at 1–1. The tiebreaker here is price, speed, and what you actually run them on.
Pricing. Both models sit in the mid-tier bracket for output-token pricing. At 1.0× the per-million-token cost, Gemini 2.5 Pro is meaningfully cheaper if your traffic is output-heavy (long completions, document generation, agent loops). Gemini 2.5 Pro makes more sense when output volume is low and absolute reasoning quality justifies the premium.
Strengths. Claude Sonnet 5 (Adaptive Reasoning, Xhigh Effort) is strongest on Intelligence Index (34.7). Gemini 2.5 Pro leads on Coding Index (33.3), Intelligence Index (16.7).
Speed. On throughput, Gemini 2.5 Pro generates tokens at 132 tok/s versus 66 tok/s — about 50% faster. On time-to-first-token, Gemini 2.5 Pro responds in 20730ms vs 24850ms, which matters most for chat-style UIs.
Provider. Anthropic and Google sell to overlapping but distinct developer audiences: Anthropic tends to ship frontier reasoning models with premium positioning, while Google often prices more aggressively. Your existing vendor relationships, billing, and SLA preferences may matter as much as the raw numbers above.
Workload cost. Workload scenarios (per million requests at 30M input + 15M output tokens): Claude Sonnet 5 (Adaptive Reasoning, Xhigh Effort) costs $210.00 ($2520/year); Gemini 2.5 Pro costs $187.50 ($2250/year). At a smaller 5M-input/2M-output scale (single-developer tool or prototype): Claude Sonnet 5 (Adaptive Reasoning, Xhigh Effort) ≈ $30.00/run, Gemini 2.5 Pro ≈ $26.25/run. At agent/realtime scale (200M input / 100M output per million requests): Claude Sonnet 5 (Adaptive Reasoning, Xhigh Effort) ≈ $1400/run, Gemini 2.5 Pro ≈ $1250/run. Gemini 2.5 Pro becomes more attractive at higher volume — the absolute per-token pricing difference compounds when you ship at scale.
Recommendation. Both models have legitimate use cases — the right answer depends on whether you are optimizing for benchmark ceiling, latency, or unit cost. Start with the cheaper / faster model, evaluate against your specific task, and only switch if the upgrade shows a meaningful lift.
Head-to-head deltas
Data from Artificial Analysis API — 12 benchmarks
Gemini 2.5 Pro is cheaper overall. Its blended price (3:1 input/output ratio) is $3.44/M tokens vs $4.00/M for Claude Sonnet 5 (Adaptive Reasoning, Xhigh Effort).
It's a tie — both models win 1 benchmarks each across 12 evaluated categories. See the detailed benchmark chart above for per-category results.
Gemini 2.5 Pro generates tokens faster at 132 tok/s vs 66 tok/s. However, Gemini 2.5 Pro has lower time-to-first-token (20.73s vs 24.85s).
Choose based on your priorities: Gemini 2.5 Pro for lower cost, both perform similarly on benchmarks, and Gemini 2.5 Pro for faster generation. For latency-sensitive apps, check the TTFT comparison above.