Model comparison

GPT-5.4 mini vs gpt-oss-120b

GPT-5.4 mini is the stronger model overall, scoring 44.8 to 36.0 on the Noometry Index. gpt-oss-120b costs 24× less per token, which makes it the better buy when GPT-5.4 mini's lead doesn't matter for your workload.

Last verified . 31 shared benchmarks.

GPT-5.4 mini OpenAI

44.8

Rank #69 Confirmed

gpt-oss-120b OpenAI

36.0

Rank #210 Confirmed

Summary

  • They share 31 benchmarks with published results for both. GPT-5.4 mini scores higher in 8 categories and gpt-oss-120b in 1 category; 9 gaps are clear of the uncertainty.
  • The widest gap is in agentic & tool use, where GPT-5.4 mini leads 29.6 to 12.1.
  • The biggest single-benchmark swing is Kagi LLM Benchmark: 37.9% for GPT-5.4 mini and 58.6% for gpt-oss-120b.
  • gpt-oss-120b is cheaper at $0.037 / $0.17 per million input/output tokens, against $0.75 / $4.50 for GPT-5.4 mini.
  • GPT-5.4 mini accepts more context: 400K tokens versus 131K.
  • gpt-oss-120b has downloadable open weights; the other is API-only.

Side by side

GPT-5.4 mini and gpt-oss-120b specifications
GPT-5.4 minigpt-oss-120b
ProviderOpenAIOpenAI
Noometry Index44.836.0
Released2026-03-172025-08-05
WeightsProprietaryOpen
Context window400K131K
Max output128K41K
Input $ / M tokens$0.75$0.037
Output $ / M tokens$4.50$0.17
Results tracked4648

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Category by category

Coding GPT-5.4 mini leads

GPT-5.4 mini: 45.0 (#67), gpt-oss-120b: 33.2 (#251)

Coding benchmarks
BenchmarkGPT-5.4 minigpt-oss-120b
SciCode49.9%36%
WeirdML60.3%48.2%
LMArena Coding14381380
ALE-Bench1,189575.62
FrontierCode27%—
SWE-bench Verified (bash only)—26%
Aider Polyglot—41.8%
LMArena WebDev1397—
AlgoTune—1.41

Agentic & Tool Use GPT-5.4 mini leads

GPT-5.4 mini: 29.6 (#74), gpt-oss-120b: 12.1 (#145)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.4 minigpt-oss-120b
Terminal-Bench—18.7%
APEX-Agents—4.4%
DeepResearch Bench36.3%—
METR Time Horizons—56.6%
Vending-Bench 2—-21.53

Reasoning GPT-5.4 mini leads

GPT-5.4 mini: 30.3 (#77), gpt-oss-120b: 19.5 (#236)

Reasoning benchmarks
BenchmarkGPT-5.4 minigpt-oss-120b
Kagi LLM Benchmark37.9%58.6%
CritPt10%1.1%
Chess Puzzles24%20%
LMArena Hard Prompts14241364
Mystery Game Puzzles11%2%
DTBench80%76.3%
LMCA40.8%22.1%
Epoch Capabilities Index148.83139.94
ARC-AGI-218.9%—
SimpleBench—22.1%
NYT Connections (extended)61.8%—
ARC-AGI-163.7%—
Thematic Generalization61.7%—
Surface Evolver Bench—25%
ForecastBench57—

Math gpt-oss-120b leads

GPT-5.4 mini: 45.4 (#63), gpt-oss-120b: 50.6 (#43)

Math benchmarks
BenchmarkGPT-5.4 minigpt-oss-120b
OTIS Mock AIME 2024-202588.9%88.9%
LMArena Math14181388
FrontierMath (Tiers 1-3)51.2%—
FrontierMath Tier 49.8%—
ProofBench21%—
Omni-MATH—68.8%
FrontierMath (Feb 2025 set)28.3%—
FrontierMath Tier 4 (v1)2.1%—

Knowledge GPT-5.4 mini leads

GPT-5.4 mini: 51.4 (#62), gpt-oss-120b: 42.3 (#89)

Knowledge benchmarks
BenchmarkGPT-5.4 minigpt-oss-120b
GPQA Diamond86.9%75.8%
Vectara Hallucination Rate5.5%14.2%
LMArena Expert14341356
SimpleQA Verified29.4%—
MMLU-Pro—79.5%
Confabulations—15.7%
GPQA (HELM)—68.4%

Multimodal Not comparable

GPT-5.4 mini: 39.0 (#51), gpt-oss-120b: —

Multimodal benchmarks
BenchmarkGPT-5.4 minigpt-oss-120b
LMArena Vision1245—

Multilingual GPT-5.4 mini leads

GPT-5.4 mini: 52.1 (#94), gpt-oss-120b: 48.2 (#142)

Multilingual benchmarks
BenchmarkGPT-5.4 minigpt-oss-120b
LMArena Non-English14051350
LMArena Chinese14461384
LMArena French14401370
LMArena German14071355
LMArena Japanese13751332
LMArena Korean13691283
LMArena Russian14171343
LMArena Spanish14031388

Instruction Following GPT-5.4 mini leads

GPT-5.4 mini: 74.3 (#99), gpt-oss-120b: 69.5 (#168)

Instruction Following benchmarks
BenchmarkGPT-5.4 minigpt-oss-120b
LMArena Instruction Following14051318
IFEval—83.6%

Long Context GPT-5.4 mini leads

GPT-5.4 mini: 42.9 (#107), gpt-oss-120b: 31.4 (#273)

Long Context benchmarks
BenchmarkGPT-5.4 minigpt-oss-120b
LMArena Longer Query14071319
Fiction.LiveBench—44.4%

Writing & Preference GPT-5.4 mini leads

GPT-5.4 mini: 64.2 (#56), gpt-oss-120b: 46.7 (#213)

Writing & Preference benchmarks
BenchmarkGPT-5.4 minigpt-oss-120b
LMArena Text14111366
LMArena Creative Writing13701274
EQ-Bench Creative Writing1665961
LMArena Multi-Turn14291340
Short-Story Creative Writing—77.1%
WildBench—84.5%

Frequently asked questions

Is GPT-5.4 mini better than gpt-oss-120b?

GPT-5.4 mini is the stronger model overall, scoring 44.8 to 36.0 on the Noometry Index. gpt-oss-120b costs 24× less per token, which makes it the better buy when GPT-5.4 mini's lead doesn't matter for your workload.

Which is cheaper, GPT-5.4 mini or gpt-oss-120b?

gpt-oss-120b is cheaper. It lists at $0.037 per million input tokens and $0.17 per million output tokens; GPT-5.4 mini lists at $0.75 and $4.50.

Is GPT-5.4 mini or gpt-oss-120b better for coding?

GPT-5.4 mini scores higher on coding benchmarks: 45.0 versus 33.2 in the Noometry coding category.

Which has the bigger context window?

GPT-5.4 mini does, with 400K tokens against 131K.

How many benchmarks do GPT-5.4 mini and gpt-oss-120b share?

31 benchmarks have published results for both models. GPT-5.4 mini has 46 scored results on Noometry and gpt-oss-120b has 48.

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