BenchLeader

Claude Opus 4.8 vs Grok 4.5

Verdict
  • Claude Opus 4.8 leads on quality: 64.7 vs 63.4.
  • Claude Opus 4.8 is stronger in agents & tools, coding, composite, instruction following.
  • Grok 4.5 is stronger in human preference, knowledge, long context, multimodal, reasoning.
  • Grok 4.5 is 3.3× cheaper ($3.00 vs $10.00 per 1M blended).
MetricClaude Opus 4.8Grok 4.5
BenchLeader Index64.763.4
Agents & tools score65.058.6
Coding score65.759.9
Composite score81.966.0
Human preference score65.666.9
Instruction following score61.6
Knowledge score66.376.0
Long context score65.366.2
Multimodal score64.464.8
Reasoning score64.268.9
Blended price $/M$10.00$3.00
Output speed58 tok/s56 tok/s
Time to first answer29.5 s12.7 s
Context window1M500k
SimpleBench64.8%70.0%
Remote Labor Index8.3%
WeirdML46.4%
APEX-Agents34.2%
FrontierCode46.5%42.4%
GSO-Bench47.1%
Epoch Capabilities Index158.3153.9
LMArena Text14731471
LMArena Hard Prompts15031495
LMArena Coding15271523
LMArena WebDev15401556
LMArena Vision12891291
LMArena Agent3.9
LiveBench75.8%
LiveBench Reasoning87.2%
LiveBench Coding68.6%
LiveBench Agentic Coding56.5%
LiveBench Mathematics90.8%
LiveBench Data Analysis73.0%
LiveBench Language82.8%
AA Intelligence Index42.039.1
IFBench62.2%
AA-LCR77.7%79.3%
MMMU-Pro80.4%
AA-Omniscience28.825.3
Terminal-Bench Hard58.3%
GPQA Diamond (AA)92.0%93.1%
Humanity's Last Exam (AA)48.7%42.7%
SciCode (AA)54.4%55.0%
τ²-Bench Telecom (AA)94.4%
LiveCodeBench87.8%
MMLU-Pro89.6%
LegalBench83.6%
CorpFin66.7%
TaxEval75.6%
Terminal-Bench 2.1 (Vals)71.9%
SWE-bench (Vals)88.6%
GPQA Diamond (Vals)92.4%
Vals Index60.9
HiL-Bench35.3%
EQ-Bench 41281
Kagi LLM Benchmark83.5%

Data as of 2026-09-09. Best configuration of each model; every score links to its source on the model pages.