Model comparison

GPT-5.4 Pro vs gpt-oss-120b

GPT-5.4 Pro is the stronger model overall, scoring 58.9 to 36.3 on the Noometry Index. gpt-oss-120b costs 961× less per token, which makes it the better buy when GPT-5.4 Pro's lead doesn't matter for your workload.

Last verified . 7 shared benchmarks.

GPT-5.4 Pro OpenAI

58.9

Rank #18 Confirmed

gpt-oss-120b OpenAI

36.3

Rank #217 Confirmed

Summary

  • They share 7 benchmarks with published results for both. GPT-5.4 Pro scores higher in 4 categories and gpt-oss-120b in 0 categories; 4 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.4 Pro leads 70.7 to 20.0.
  • The biggest single-benchmark swing is SimpleBench: 74.1% for GPT-5.4 Pro and 22.1% for gpt-oss-120b.
  • gpt-oss-120b is cheaper at $0.037 / $0.17 per million input/output tokens, against $30 / $180 for GPT-5.4 Pro.
  • GPT-5.4 Pro accepts more context: 1.05M tokens versus 131K.
  • gpt-oss-120b has downloadable open weights; the other is API-only.

Side by side

GPT-5.4 Pro and gpt-oss-120b specifications
GPT-5.4 Progpt-oss-120b
ProviderOpenAIOpenAI
Noometry Index58.936.3
Released2026-03-052025-08-05
WeightsProprietaryOpen
Context window1.05M131K
Max output128K41K
Input $ / M tokens$30$0.037
Output $ / M tokens$180$0.17
Results tracked1648

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Category by category

Coding GPT-5.4 Pro leads

GPT-5.4 Pro: 43.2 (#90), gpt-oss-120b: 33.5 (#256)

Coding benchmarks
BenchmarkGPT-5.4 Progpt-oss-120b
WeirdML57.4%48.2%
SWE-bench Verified (bash only)—26%
Aider Polyglot—41.8%
SciCode—36%
LMArena Coding—1380
ALE-Bench—575.62
AlgoTune—1.41

Agentic & Tool Use Not comparable

GPT-5.4 Pro: —, gpt-oss-120b: 12.2 (#153)

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

Reasoning GPT-5.4 Pro leads

GPT-5.4 Pro: 70.7 (#13), gpt-oss-120b: 20.0 (#245)

Reasoning benchmarks
BenchmarkGPT-5.4 Progpt-oss-120b
SimpleBench74.1%22.1%
CritPt30%1.1%
Chess Puzzles58.6%20%
Epoch Capabilities Index158.93139.93
ARC-AGI-283.3%—
Kagi LLM Benchmark—58.6%
ARC-AGI-194.5%—
EnigmaEval23.8%—
LMArena Hard Prompts—1364
Mystery Game Puzzles—2%
DTBench—76.3%
LMCA—22.1%
Surface Evolver Bench—25%

Math GPT-5.4 Pro leads

GPT-5.4 Pro: 72.4 (#22), gpt-oss-120b: 52.5 (#50)

Math benchmarks
BenchmarkGPT-5.4 Progpt-oss-120b
FrontierMath (Tiers 1-3)82.5%—
FrontierMath Tier 458.5%—
OTIS Mock AIME 2024-2025—88.9%
Omni-MATH—68.8%
LMArena Math—1389
FrontierMath (Feb 2025 set)50%—
FrontierMath Tier 4 (v1)37.5%—

Knowledge GPT-5.4 Pro leads

GPT-5.4 Pro: 68.3 (#7), gpt-oss-120b: 42.4 (#96)

Knowledge benchmarks
BenchmarkGPT-5.4 Progpt-oss-120b
GPQA Diamond94.6%75.8%
Vectara Hallucination Rate8.3%14.2%
Humanity's Last Exam44.3%—
SimpleQA Verified46.3%—
MMLU-Pro—79.5%
Confabulations—15.7%
GPQA (HELM)—68.4%
LMArena Expert—1356

Multilingual Not comparable

GPT-5.4 Pro: —, gpt-oss-120b: 48.0 (#147)

Multilingual benchmarks
BenchmarkGPT-5.4 Progpt-oss-120b
LMArena Non-English—1351
LMArena Chinese—1385
LMArena French—1369
LMArena German—1353
LMArena Japanese—1331
LMArena Korean—1282
LMArena Russian—1343
LMArena Spanish—1389

Instruction Following Not comparable

GPT-5.4 Pro: —, gpt-oss-120b: 69.3 (#173)

Instruction Following benchmarks
BenchmarkGPT-5.4 Progpt-oss-120b
IFEval—83.6%
LMArena Instruction Following—1318

Long Context Not comparable

GPT-5.4 Pro: —, gpt-oss-120b: 31.4 (#278)

Long Context benchmarks
BenchmarkGPT-5.4 Progpt-oss-120b
Fiction.LiveBench—44.4%
LMArena Longer Query—1319

Writing & Preference Not comparable

GPT-5.4 Pro: —, gpt-oss-120b: 46.5 (#217)

Writing & Preference benchmarks
BenchmarkGPT-5.4 Progpt-oss-120b
LMArena Text—1365
LMArena Creative Writing—1275
Short-Story Creative Writing—77.1%
EQ-Bench Creative Writing—961
WildBench—84.5%
LMArena Multi-Turn—1340

Frequently asked questions

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

GPT-5.4 Pro is the stronger model overall, scoring 58.9 to 36.3 on the Noometry Index. gpt-oss-120b costs 961× less per token, which makes it the better buy when GPT-5.4 Pro's lead doesn't matter for your workload.

Which is cheaper, GPT-5.4 Pro 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 Pro lists at $30 and $180.

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

GPT-5.4 Pro scores higher on coding benchmarks: 43.2 versus 33.5 in the Noometry coding category.

Which has the bigger context window?

GPT-5.4 Pro does, with 1.05M tokens against 131K.

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

7 benchmarks have published results for both models. GPT-5.4 Pro has 16 scored results on Noometry and gpt-oss-120b has 48.

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