Model comparison

gpt-oss-120b vs Grok 4.20 Multi-Agent

Grok 4.20 Multi-Agent is the stronger model overall, scoring 45.5 to 36.0 on the Noometry Index. gpt-oss-120b costs 22× less per token, which makes it the better buy when Grok 4.20 Multi-Agent's lead doesn't matter for your workload.

Last verified . 17 shared benchmarks.

gpt-oss-120b OpenAI

36.0

Rank #210 Confirmed

Grok 4.20 Multi-Agent xAI

45.5

Rank #62 Confirmed

Summary

  • They share 17 benchmarks with published results for both. gpt-oss-120b scores higher in 2 categories and Grok 4.20 Multi-Agent in 6 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Grok 4.20 Multi-Agent leads 42.4 to 19.5.
  • gpt-oss-120b is cheaper at $0.037 / $0.17 per million input/output tokens, against $1.25 / $2.50 for Grok 4.20 Multi-Agent.
  • Grok 4.20 Multi-Agent accepts more context: 1M tokens versus 131K.
  • gpt-oss-120b has downloadable open weights; the other is API-only.

Side by side

gpt-oss-120b and Grok 4.20 Multi-Agent specifications
gpt-oss-120bGrok 4.20 Multi-Agent
ProviderOpenAIxAI
Noometry Index36.045.5
Released2025-08-052026-03-09
WeightsOpenProprietary
Context window131K1M
Max output41K30K
Input $ / M tokens$0.037$1.25
Output $ / M tokens$0.17$2.50
Results tracked4820

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding Grok 4.20 Multi-Agent leads

gpt-oss-120b: 33.2 (#251), Grok 4.20 Multi-Agent: 42.4 (#91)

Coding benchmarks
Benchmarkgpt-oss-120bGrok 4.20 Multi-Agent
LMArena Coding13801458
SWE-bench Verified (bash only)26%—
Aider Polyglot41.8%—
SciCode36%—
WeirdML48.2%—
ALE-Bench575.62—
AlgoTune1.41—

Agentic & Tool Use Not comparable

gpt-oss-120b: 12.1 (#145), Grok 4.20 Multi-Agent: —

Agentic & Tool Use benchmarks
Benchmarkgpt-oss-120bGrok 4.20 Multi-Agent
Terminal-Bench18.7%—
APEX-Agents4.4%—
LMArena Search—1204
METR Time Horizons56.6%—
Vending-Bench 2-21.53—

Reasoning Grok 4.20 Multi-Agent leads

gpt-oss-120b: 19.5 (#236), Grok 4.20 Multi-Agent: 42.4 (#44)

Reasoning benchmarks
Benchmarkgpt-oss-120bGrok 4.20 Multi-Agent
LMArena Hard Prompts13641448
SimpleBench22.1%—
Kagi LLM Benchmark58.6%—
NYT Connections (extended)—89.6%
CritPt1.1%—
Chess Puzzles20%—
Mystery Game Puzzles2%—
DTBench76.3%—
LMCA22.1%—
Surface Evolver Bench25%—
Epoch Capabilities Index139.94—

Math gpt-oss-120b leads

gpt-oss-120b: 50.6 (#43), Grok 4.20 Multi-Agent: 36.6 (#106)

Math benchmarks
Benchmarkgpt-oss-120bGrok 4.20 Multi-Agent
LMArena Math13881441
OTIS Mock AIME 2024-202588.9%—
Omni-MATH68.8%—

Knowledge gpt-oss-120b leads

gpt-oss-120b: 42.3 (#89), Grok 4.20 Multi-Agent: 39.7 (#116)

Knowledge benchmarks
Benchmarkgpt-oss-120bGrok 4.20 Multi-Agent
LMArena Expert13561445
GPQA Diamond75.8%—
MMLU-Pro79.5%—
Confabulations15.7%—
Vectara Hallucination Rate14.2%—
GPQA (HELM)68.4%—

Multimodal Not comparable

gpt-oss-120b: —, Grok 4.20 Multi-Agent: 39.8 (#44)

Multimodal benchmarks
Benchmarkgpt-oss-120bGrok 4.20 Multi-Agent
LMArena Vision—1259

Multilingual Grok 4.20 Multi-Agent leads

gpt-oss-120b: 48.2 (#142), Grok 4.20 Multi-Agent: 54.6 (#40)

Multilingual benchmarks
Benchmarkgpt-oss-120bGrok 4.20 Multi-Agent
LMArena Non-English13501440
LMArena Chinese13841475
LMArena French13701467
LMArena German13551456
LMArena Japanese13321405
LMArena Korean12831416
LMArena Russian13431457
LMArena Spanish13881447

Instruction Following Grok 4.20 Multi-Agent leads

gpt-oss-120b: 69.5 (#168), Grok 4.20 Multi-Agent: 75.0 (#80)

Instruction Following benchmarks
Benchmarkgpt-oss-120bGrok 4.20 Multi-Agent
LMArena Instruction Following13181420
IFEval83.6%—

Long Context Grok 4.20 Multi-Agent leads

gpt-oss-120b: 31.4 (#273), Grok 4.20 Multi-Agent: 43.7 (#84)

Long Context benchmarks
Benchmarkgpt-oss-120bGrok 4.20 Multi-Agent
LMArena Longer Query13191430
Fiction.LiveBench44.4%—

Writing & Preference Grok 4.20 Multi-Agent leads

gpt-oss-120b: 46.7 (#213), Grok 4.20 Multi-Agent: 64.1 (#57)

Writing & Preference benchmarks
Benchmarkgpt-oss-120bGrok 4.20 Multi-Agent
LMArena Text13661450
LMArena Creative Writing12741435
LMArena Multi-Turn13401451
Short-Story Creative Writing77.1%—
EQ-Bench Creative Writing961—
WildBench84.5%—

Frequently asked questions

Is gpt-oss-120b better than Grok 4.20 Multi-Agent?

Grok 4.20 Multi-Agent is the stronger model overall, scoring 45.5 to 36.0 on the Noometry Index. gpt-oss-120b costs 22× less per token, which makes it the better buy when Grok 4.20 Multi-Agent's lead doesn't matter for your workload.

Which is cheaper, gpt-oss-120b or Grok 4.20 Multi-Agent?

gpt-oss-120b is cheaper. It lists at $0.037 per million input tokens and $0.17 per million output tokens; Grok 4.20 Multi-Agent lists at $1.25 and $2.50.

Is gpt-oss-120b or Grok 4.20 Multi-Agent better for coding?

Grok 4.20 Multi-Agent scores higher on coding benchmarks: 42.4 versus 33.2 in the Noometry coding category.

Which has the bigger context window?

Grok 4.20 Multi-Agent does, with 1M tokens against 131K.

How many benchmarks do gpt-oss-120b and Grok 4.20 Multi-Agent share?

17 benchmarks have published results for both models. gpt-oss-120b has 48 scored results on Noometry and Grok 4.20 Multi-Agent has 20.

Related comparisons

Go deeper