Model comparison

GPT-5.1 vs Mercury

GPT-5.1 is the stronger model overall, scoring 48.8 to 37.3 on the Noometry Index.

Last verified . 8 shared benchmarks.

GPT-5.1 OpenAI

48.8

Rank #47 Confirmed

Mercury Inception

37.3

Rank #192 Confirmed

Summary

  • They share 8 benchmarks with published results for both. GPT-5.1 scores higher in 6 categories and Mercury in 0 categories; 6 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.1 leads 39.9 to 16.8.

Side by side

GPT-5.1 and Mercury specifications
GPT-5.1Mercury
ProviderOpenAIInception
Noometry Index48.837.3
Released2025-11-13—
WeightsProprietaryProprietary
Context window400K—
Max output128K—
Input $ / M tokens$1.25—
Output $ / M tokens$10—
Results tracked639

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Category by category

Coding GPT-5.1 leads

GPT-5.1: 46.9 (#59), Mercury: 38.1 (#164)

Coding benchmarks
BenchmarkGPT-5.1Mercury
LMArena Coding14541323
SWE-bench Verified68%—
SWE-bench Verified (bash only)66%—
LMArena WebDev1395—
SciCode43.3%—
GSO13.7%—
WeirdML60.8%—
LiveBench Coding72.5%—
ALE-Bench1,192—

Agentic & Tool Use Not comparable

GPT-5.1: 32.5 (#55), Mercury: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1Mercury
Terminal-Bench47.6%—
DeepResearch Bench42.8%—
LMArena Search1199—
Vending-Bench 21,473—

Reasoning GPT-5.1 leads

GPT-5.1: 39.9 (#50), Mercury: 16.8 (#288)

Reasoning benchmarks
BenchmarkGPT-5.1Mercury
LMArena Hard Prompts14571284
ARC-AGI-217.6%—
SimpleBench53.2%—
Kagi LLM Benchmark—21.6%
ARC-AGI-172.8%—
CritPt4.9%—
Chess Puzzles32%—
EnigmaEval11.2%—
LiveBench Reasoning95.8%—
Mystery Game Puzzles19%—
DTBench90.1%—
LiveBench Data Analysis72.1%—
LMCA43.9%—
Epoch Capabilities Index149.66—
ForecastBench58.1—
LiveBench78.8%—

Math Not comparable

GPT-5.1: 50.3 (#45), Mercury: —

Math benchmarks
BenchmarkGPT-5.1Mercury
OTIS Mock AIME 2024-202588.6%—
Omni-MATH46.4%—
LiveBench Math94.5%—
LMArena Math1446—
FrontierMath (Feb 2025 set)31%—
FrontierMath Tier 4 (v1)12.5%—

Knowledge Not comparable

GPT-5.1: 50.5 (#65), Mercury: —

Knowledge benchmarks
BenchmarkGPT-5.1Mercury
GPQA Diamond87.6%—
Humanity's Last Exam23.7%—
SimpleQA Verified48%—
MMLU-Pro57.9%—
Vectara Hallucination Rate10.9%—
GPQA (HELM)44.2%—
LMArena Expert1470—

Multimodal Not comparable

GPT-5.1: 44.0 (#17), Mercury: —

Multimodal benchmarks
BenchmarkGPT-5.1Mercury
LMArena Vision1250—
VPCT58.7%—
LMArena Document1403—

Multilingual GPT-5.1 leads

GPT-5.1: 54.0 (#51), Mercury: 41.7 (#201)

Multilingual benchmarks
BenchmarkGPT-5.1Mercury
LMArena Non-English14311259
LMArena Chinese1495—
LMArena French1451—
LMArena German1439—
LMArena Japanese1453—
LMArena Korean1401—
LMArena Russian1435—
LMArena Spanish1430—

Instruction Following GPT-5.1 leads

GPT-5.1: 84.0 (#1), Mercury: 65.3 (#220)

Instruction Following benchmarks
BenchmarkGPT-5.1Mercury
LMArena Instruction Following14421238
LiveBench Instruction Following93.3%—
IFEval93.5%—

Long Context GPT-5.1 leads

GPT-5.1: 47.6 (#14), Mercury: 38.3 (#193)

Long Context benchmarks
BenchmarkGPT-5.1Mercury
LMArena Longer Query14481264
CL-bench23.7%—
CL-bench Life17.3%—

Writing & Preference GPT-5.1 leads

GPT-5.1: 64.7 (#53), Mercury: 46.2 (#216)

Writing & Preference benchmarks
BenchmarkGPT-5.1Mercury
LMArena Text14431282
LMArena Creative Writing14271186
LMArena Multi-Turn14491283
WildBench86.3%—
LiveBench Language80.2%—

Frequently asked questions

Is GPT-5.1 better than Mercury?

GPT-5.1 is the stronger model overall, scoring 48.8 to 37.3 on the Noometry Index.

Is GPT-5.1 or Mercury better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.9 versus 38.1 in the Noometry coding category.

How many benchmarks do GPT-5.1 and Mercury share?

8 benchmarks have published results for both models. GPT-5.1 has 63 scored results on Noometry and Mercury has 9.

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