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Compare / head-to-head

Claude Opus 4.6vsGrok 4 Fast Reasoning

Claude Opus 4.6 leads 1 of 1 shared benchmark. 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
1 – 0
Claude Opus 4.6 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 4.6
Anthropic · released 2026-02-05
textvision
Context
1M
Max out
128K
Input /1M
$5
Output /1M
$25
Cached /1M
$0.5
Scores
19 · 9 core
Grok 4 Fast Reasoning
xAI · released 2025-09-19
text
Context
2M
Max out
Input /1M
$0.2
Output /1M
$0.5
Cached /1M
$0.05
Scores
12 · 4 core
Quality

Benchmark matrix

BenchmarkClaude Opus 4.6Grok 4 Fast ReasoningΔEdge
Reported by both · 1
GPQA Diamond91.3% 85.7% +5.6 ptClaude Opus 4.6
Only Claude Opus 4.6 reports · 17
SWE-bench Verified80.8% not reported
AIME 202696.7% matharenanot reported
LMArena Elo1497.5 not reported
ARC-AGI-2 (Verified)68.8% not reported
FrontierMath Tier 4 v2 (Epoch AI run)26.8% epochnot reported
FrontierMath Tiers 1-3 v2 (Epoch AI run)66% epochnot reported
MCP Atlas59.5% not reported
MMMLU91.1% not reported
MMMU-Pro (no tools)73.9% not reported
MMMU-Pro (with tools)77.3% not reported
OSWorld-Verified72.7% not reported
OTIS Mock AIME 2024-2025 (Epoch AI run)94.4% epochnot reported
SimpleQA Verified47% epochnot reported
SWE-bench Verified (Epoch AI run)78.7% epochnot reported
Tau2-bench Retail91.9% not reported
Tau2-bench Telecom99.3% not reported
Terminal-Bench 2.065.4% not reported
Only Grok 4 Fast Reasoning reports · 11
AIME 2025not reported92%
Humanity's Last Exam (no tools)not reported20%
BrowseCompnot reported44.9%
BrowseComp (zh)not reported51.2%
HMMT 2025 (no tools)not reported93.3%
LiveCodeBench (Jan-May)not reported80%
Reka Research Evalnot reported66%
Search Arena Elonot reported1163
SimpleQAnot reported95%
X Bench Deepsearch (zh)not reported74%
X Browsenot reported58%
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 4.6 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

SpecClaude Opus 4.6Grok 4 Fast ReasoningEdge
Context window1M tokens2M tokensGrok 4 Fast Reasoning
Max output128K 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$0.7Grok 4 Fast Reasoning
Modalitiestext · visiontextClaude Opus 4.6
Released2026-02-052025-09-19
Cited benchmark scores1912
Reliability

Provider status

All providers
More matchups

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Public benchmarks are a starting point. Run Claude Opus 4.6 and Grok 4 Fast Reasoning on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.