Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | Gemini 2.5 Pro | Claude Sonnet 5 (Adaptive Reasoning, Low Effort) |
|---|---|---|
| Input ($/M tokens) | $1.25 | $2 |
| Output ($/M tokens) | $10 | $10 |
Verdict. Gemini 2.5 Pro and Claude Sonnet 5 (Adaptive Reasoning, Low Effort) 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, Claude Sonnet 5 (Adaptive Reasoning, Low Effort) is meaningfully cheaper if your traffic is output-heavy (long completions, document generation, agent loops). Claude Sonnet 5 (Adaptive Reasoning, Low Effort) makes more sense when output volume is low and absolute reasoning quality justifies the premium.
Strengths. Gemini 2.5 Pro is strongest on Coding Index (33.3), Intelligence Index (16.7). Claude Sonnet 5 (Adaptive Reasoning, Low Effort) leads on Intelligence Index (24.7).
Speed. On throughput, Gemini 2.5 Pro generates tokens at 132 tok/s versus 57 tok/s — about 57% faster. On time-to-first-token, Claude Sonnet 5 (Adaptive Reasoning, Low Effort) responds in 980ms vs 20730ms, which matters most for chat-style UIs.
Provider. Google and Anthropic sell to overlapping but distinct developer audiences: Google tends to ship frontier reasoning models with premium positioning, while Anthropic 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): Gemini 2.5 Pro costs $187.50 ($2250/year); Claude Sonnet 5 (Adaptive Reasoning, Low Effort) costs $210.00 ($2520/year). At a smaller 5M-input/2M-output scale (single-developer tool or prototype): Gemini 2.5 Pro ≈ $26.25/run, Claude Sonnet 5 (Adaptive Reasoning, Low Effort) ≈ $30.00/run. At agent/realtime scale (200M input / 100M output per million requests): Gemini 2.5 Pro ≈ $1250/run, Claude Sonnet 5 (Adaptive Reasoning, Low Effort) ≈ $1400/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, Low 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 57 tok/s. However, Claude Sonnet 5 (Adaptive Reasoning, Low Effort) has lower time-to-first-token (0.98s vs 20.73s).
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.