Model comparison

GPT-5.4 vs Mercury

GPT-5.4 is the stronger model overall, scoring 59.4 to 37.6 on the Noometry Index.

Last verified . 9 shared benchmarks.

GPT-5.4 OpenAI

59.4

Rank #16 Confirmed

Mercury Inception

37.6

Rank #199 Confirmed

Summary

  • They share 9 benchmarks with published results for both. GPT-5.4 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-5.4 leads 61.8 to 17.5.
  • The biggest single-benchmark swing is Kagi LLM Benchmark: 63.8% for GPT-5.4 and 21.6% for Mercury.

Side by side

GPT-5.4 and Mercury specifications
GPT-5.4Mercury
ProviderOpenAIInception
Noometry Index59.437.6
Released2026-03-05—
WeightsProprietaryProprietary
Context window1.05M—
Max output128K—
Input $ / M tokens$2.50—
Output $ / M tokens$15—
Results tracked689

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Category by category

Coding GPT-5.4 leads

GPT-5.4: 52.6 (#33), Mercury: 38.7 (#170)

Coding benchmarks
BenchmarkGPT-5.4Mercury
LMArena Coding14971322
SWE-bench Verified76.9%—
DeepSWE51.8%—
LMArena WebDev1465—
SciCode56.6%—
GSO31.4%—
WeirdML77.7%—
MirrorCode15.6%—
ALE-Bench1,607—
AlgoTune1.85—

Agentic & Tool Use Not comparable

GPT-5.4: 46.5 (#13), Mercury: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.4Mercury
Terminal-Bench81.8%—
APEX-Agents52.4%—
τ²-bench Banking39.4%—
DeepResearch Bench35.1%—
PostTrainBench19%—
GBAEval45.1%—
LMArena Search1197—
METR Time Horizons74.3%—
Vending-Bench 26,144—

Reasoning GPT-5.4 leads

GPT-5.4: 61.8 (#19), Mercury: 17.5 (#293)

Reasoning benchmarks
BenchmarkGPT-5.4Mercury
Kagi LLM Benchmark63.8%21.6%
LMArena Hard Prompts14851285
ARC-AGI-274%—
NYT Connections (extended)91.3%—
ARC-AGI-193.7%—
CritPt23.4%—
Chess Puzzles44%—
EnigmaEval16%—
Thematic Generalization80%—
EBR-Bench25.4%—
Mystery Game Puzzles37%—
DTBench94.4%—
LMCA52%—
Epoch Capabilities Index156.81—
ForecastBench59.5—

Math Not comparable

GPT-5.4: 73.5 (#19), Mercury: —

Knowledge Not comparable

GPT-5.4: 65.3 (#14), Mercury: —

Knowledge benchmarks
BenchmarkGPT-5.4Mercury
GPQA Diamond93.3%—
Humanity's Last Exam36.2%—
SimpleQA Verified45.1%—
Vectara Hallucination Rate7%—
LMArena Expert1507—

Multimodal Not comparable

GPT-5.4: 43.7 (#20), Mercury: —

Multimodal benchmarks
BenchmarkGPT-5.4Mercury
LMArena Vision1303—
Blueprint-Bench 227.1%—
Furniture Assembly37.5%—
LMArena Document1471—

Multilingual GPT-5.4 leads

GPT-5.4: 56.2 (#23), Mercury: 41.6 (#206)

Multilingual benchmarks
BenchmarkGPT-5.4Mercury
LMArena Non-English14651260
LMArena Chinese1519—
LMArena French1493—
LMArena German1472—
LMArena Japanese1485—
LMArena Korean1448—
LMArena Russian1480—
LMArena Spanish1454—

Instruction Following GPT-5.4 leads

GPT-5.4: 77.1 (#27), Mercury: 65.2 (#224)

Instruction Following benchmarks
BenchmarkGPT-5.4Mercury
LMArena Instruction Following14691239

Long Context GPT-5.4 leads

GPT-5.4: 50.3 (#8), Mercury: 38.4 (#198)

Long Context benchmarks
BenchmarkGPT-5.4Mercury
LMArena Longer Query14731266
CL-bench27.9%—
CL-bench Life21.7%—

Writing & Preference GPT-5.4 leads

GPT-5.4: 71.9 (#17), Mercury: 46.2 (#221)

Writing & Preference benchmarks
BenchmarkGPT-5.4Mercury
LMArena Text14691282
LMArena Creative Writing14391191
LMArena Multi-Turn14821282
EQ-Bench Creative Writing1840—
EQ-Bench 41272—

Frequently asked questions

Is GPT-5.4 better than Mercury?

GPT-5.4 is the stronger model overall, scoring 59.4 to 37.6 on the Noometry Index.

Is GPT-5.4 or Mercury better for coding?

GPT-5.4 scores higher on coding benchmarks: 52.6 versus 38.7 in the Noometry coding category.

How many benchmarks do GPT-5.4 and Mercury share?

9 benchmarks have published results for both models. GPT-5.4 has 68 scored results on Noometry and Mercury has 9.

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