Compare / head-to-head
Gemini 2.5 ProvsGrok 4 Fast Reasoning
Gemini 2.5 Pro leads 2 of 3 shared benchmarks. Grok 4 Fast Reasoning is 16.1x cheaper per token. Grok 4 Fast Reasoning has the larger context window (2M tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
2 – 1
Gemini 2.5 Pro leads
Cheaper per token
Grok 4 Fast Reasoning
16.1x cheaper, input + output
Larger context
Grok 4 Fast Reasoning
2M tokens
Provider uptime (30d)
100% · —
Google · xAI
Gemini 2.5 Pro
Google · released 2025-06-17
textvisionaudio
Grok 4 Fast Reasoning
xAI · released 2025-09-19
text
Quality
Benchmark matrix
3 shared · 9 only Gemini 2.5 Pro · 9 only Grok 4 Fast Reasoning| Benchmark | Gemini 2.5 Pro | Grok 4 Fast Reasoning | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 3 | ||||
| GPQA Diamond | 86.4% ↗ | 85.7% ↗ | +0.7 pt | Gemini 2.5 Pro |
| AIME 2025 | 88% ↗ | 92% ↗ | -4 pt | Grok 4 Fast Reasoning |
| Humanity's Last Exam (no tools) | 21.6% ↗ | 20% ↗ | +1.6 pt | Gemini 2.5 Pro |
| Only Gemini 2.5 Pro reports · 9 | ||||
| SWE-bench Verified | 59.6% ↗ | not reported | — | — |
| LMArena Elo | 1457.8 ↗ | not reported | — | — |
| Aider Polyglot | 82.2% ↗ | not reported | — | — |
| FrontierMath Tier 4 v2 (Epoch AI run) | 0% ↗epoch | not reported | — | — |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 24.6% ↗epoch | not reported | — | — |
| LiveCodeBench | 74.2% ↗ | not reported | — | — |
| MMMU | 82% ↗ | not reported | — | — |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 84.7% ↗epoch | not reported | — | — |
| SWE-bench Verified (Epoch AI run) | 57.6% ↗epoch | not reported | — | — |
| Only Grok 4 Fast Reasoning reports · 9 | ||||
| BrowseComp | not reported | 44.9% ↗ | — | — |
| BrowseComp (zh) | not reported | 51.2% ↗ | — | — |
| HMMT 2025 (no tools) | not reported | 93.3% ↗ | — | — |
| LiveCodeBench (Jan-May) | not reported | 80% ↗ | — | — |
| Reka Research Eval | not reported | 66% ↗ | — | — |
| Search Arena Elo | not reported | 1163 ↗ | — | — |
| SimpleQA | not reported | 95% ↗ | — | — |
| X Bench Deepsearch (zh) | not reported | 74% ↗ | — | — |
| X Browse | not reported | 58% ↗ | — | — |
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 Gemini 2.5 Pro minus Grok 4 Fast Reasoning 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 | Gemini 2.5 Pro | Grok 4 Fast Reasoning | Edge |
|---|---|---|---|
| Context window | 1.0M tokens | 2M tokens | Grok 4 Fast Reasoning |
| Max output | 66K tokens | — | — |
| Input price / 1M | $1.25 ↗ | $0.2 ↗ | Grok 4 Fast Reasoning |
| Output price / 1M | $10 ↗ | $0.5 ↗ | Grok 4 Fast Reasoning |
| Cached input / 1M | $0.125 ↗ | $0.05 ↗ | Grok 4 Fast Reasoning |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $11.25 | $0.7 | Grok 4 Fast Reasoning |
| Modalities | text · vision · audio | text | Gemini 2.5 Pro |
| Released | 2025-06-17 | 2025-09-19 | — |
| Cited benchmark scores | 14 | 12 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
Gemini 2.5 Pro vs …
Models sharing the most benchmarksMore matchups
Grok 4 Fast Reasoning vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run Gemini 2.5 Pro and Grok 4 Fast Reasoning on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.