Compare / head-to-head
Claude Opus 4.8vsGrok 4 Fast Reasoning
Claude Opus 4.8 leads 3 of 3 shared benchmarks. Grok 4 Fast Reasoning is 42.9x 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
3 – 0
Claude Opus 4.8 leads
Cheaper per token
Grok 4 Fast Reasoning
42.9x cheaper, input + output
Larger context
Grok 4 Fast Reasoning
2M tokens
Provider uptime (30d)
100% · —
Anthropic · xAI
Claude Opus 4.8
Anthropic · released 2026-05-28
textvision
Grok 4 Fast Reasoning
xAI · released 2025-09-19
text
Quality
Benchmark matrix
3 shared · 13 only Claude Opus 4.8 · 9 only Grok 4 Fast Reasoning| Benchmark | Claude Opus 4.8 | Grok 4 Fast Reasoning | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 3 | ||||
| GPQA Diamond | 93.6% ↗ | 85.7% ↗ | +7.9 pt | Claude Opus 4.8 |
| Humanity's Last Exam (no tools) | 49.8% ↗ | 20% ↗ | +29.8 pt | Claude Opus 4.8 |
| BrowseComp | 84.3% ↗ | 44.9% ↗ | +39.4 pt | Claude Opus 4.8 |
| Only Claude Opus 4.8 reports · 13 | ||||
| SWE-bench Verified | 88.6% ↗ | not reported | — | — |
| AIME 2026 | 100% ↗matharena ⚠ | not reported | — | — |
| LMArena Elo | 1452.7 ↗ | not reported | — | — |
| FrontierMath Tier 4 v2 (Epoch AI run) | 56.1% ↗epoch | not reported | — | — |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 80% ↗epoch | not reported | — | — |
| Humanity's Last Exam (with tools) | 57.9% ↗ | not reported | — | — |
| OSWorld-Verified | 83.4% ↗ | not reported | — | — |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 98.3% ↗epoch | not reported | — | — |
| SimpleQA Verified | 53% ↗epoch | not reported | — | — |
| SWE-bench Multilingual | 84.4% ↗ | not reported | — | — |
| SWE-bench Multimodal | 38.4% ↗ | not reported | — | — |
| SWE-Bench Pro | 69.2% ↗ | not reported | — | — |
| Terminal-Bench 2.1 | 74.6% ↗ | not reported | — | — |
| Only Grok 4 Fast Reasoning reports · 9 | ||||
| AIME 2025 | not reported | 92% ↗ | — | — |
| 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 Claude Opus 4.8 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 | Claude Opus 4.8 | Grok 4 Fast Reasoning | Edge |
|---|---|---|---|
| Context window | 1M tokens | 2M tokens | Grok 4 Fast Reasoning |
| Max output | 128K tokens | — | — |
| Input price / 1M | $5 ↗ | $0.2 ↗ | Grok 4 Fast Reasoning |
| Output price / 1M | $25 ↗ | $0.5 ↗ | Grok 4 Fast Reasoning |
| Cached input / 1M | $0.5 ↗ | $0.05 ↗ | Grok 4 Fast Reasoning |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $30 | $0.7 | Grok 4 Fast Reasoning |
| Modalities | text · vision | text | Claude Opus 4.8 |
| Released | 2026-05-28 | 2025-09-19 | — |
| Cited benchmark scores | 17 | 12 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
Claude Opus 4.8 vs …
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Grok 4 Fast Reasoning vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
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