Compare / head-to-head
Claude Sonnet 4.5vsGemini 2.5 Flash
Claude Sonnet 4.5 leads 4 of 4 shared benchmarks. Gemini 2.5 Flash is 6.4x cheaper per token. Gemini 2.5 Flash has the larger context window (1.0M tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
4 – 0
Claude Sonnet 4.5 leads
Cheaper per token
Gemini 2.5 Flash
6.4x cheaper, input + output
Larger context
Gemini 2.5 Flash
1.0M tokens
Provider uptime (30d)
100% · 100%
Anthropic · Google
Claude Sonnet 4.5
Anthropic · released 2025-09-29
textvision
Gemini 2.5 Flash
Google · released 2025-06-17
textvisionaudio
Quality
Benchmark matrix
4 shared · 16 only Claude Sonnet 4.5 · 4 only Gemini 2.5 Flash| Benchmark | Claude Sonnet 4.5 | Gemini 2.5 Flash | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 4 | ||||
| SWE-bench Verified | 77.2% ↗ | 48.9% ↗ | +28.3 pt | Claude Sonnet 4.5 |
| GPQA Diamond | 83.4% ↗ | 82.8% ↗ | +0.6 pt | Claude Sonnet 4.5 |
| AIME 2025 | 84.2% ↗matharena ⚠ | 72% ↗ | +12.2 pt | Claude Sonnet 4.5 |
| Humanity's Last Exam (no tools) | 17.7% ↗ | 11% ↗ | +6.7 pt | Claude Sonnet 4.5 |
| Only Claude Sonnet 4.5 reports · 16 | ||||
| ARC-AGI-2 (Verified) | 13.6% ↗ | not reported | — | — |
| FrontierMath Tier 4 v2 (Epoch AI run) | 2.4% ↗epoch | not reported | — | — |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 23.9% ↗epoch | not reported | — | — |
| GDPval-AA | 1276 ↗ | not reported | — | — |
| Humanity's Last Exam (with tools) | 33.6% ↗ | not reported | — | — |
| MCP Atlas | 43.8% ↗ | not reported | — | — |
| MMMLU | 89.5% ↗ | not reported | — | — |
| MMMU-Pro (no tools) | 63.4% ↗ | not reported | — | — |
| MMMU-Pro (with tools) | 68.9% ↗ | not reported | — | — |
| OSWorld-Verified | 61.4% ↗ | not reported | — | — |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 77.8% ↗epoch | not reported | — | — |
| SimpleQA Verified | 30.7% ↗epoch | not reported | — | — |
| SWE-bench Verified (Epoch AI run) | 71.3% ↗epoch | not reported | — | — |
| Tau2-bench Retail | 86.2% ↗ | not reported | — | — |
| Tau2-bench Telecom | 98% ↗ | not reported | — | — |
| Terminal-Bench 2.0 | 51% ↗ | not reported | — | — |
| Only Gemini 2.5 Flash reports · 4 | ||||
| LMArena Elo | not reported | 1417.3 ↗ | — | — |
| Aider Polyglot | not reported | 56.7% ↗ | — | — |
| LiveCodeBench | not reported | 59.3% ↗ | — | — |
| MMMU | not reported | 79.7% ↗ | — | — |
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is Claude Sonnet 4.5 minus Gemini 2.5 Flash in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing
Side by side
Official pricing pages and model cards| Spec | Claude Sonnet 4.5 | Gemini 2.5 Flash | Edge |
|---|---|---|---|
| Context window | 200K tokens | 1.0M tokens | Gemini 2.5 Flash |
| Max output | 64K tokens | 66K tokens | Gemini 2.5 Flash |
| Input price / 1M | $3 ↗ | $0.3 ↗ | Gemini 2.5 Flash |
| Output price / 1M | $15 ↗ | $2.5 ↗ | Gemini 2.5 Flash |
| Cached input / 1M | $0.3 ↗ | $0.03 ↗ | Gemini 2.5 Flash |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $18 | $2.8 | Gemini 2.5 Flash |
| Modalities | text · vision | text · vision · audio | Gemini 2.5 Flash |
| Released | 2025-09-29 | 2025-06-17 | — |
| Cited benchmark scores | 21 | 9 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
Claude Sonnet 4.5 vs …
Models sharing the most benchmarksMore matchups
Gemini 2.5 Flash vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run Claude Sonnet 4.5 and Gemini 2.5 Flash on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.