Model comparison

gpt-oss-20b vs Grok 4.20 Multi-Agent

Grok 4.20 Multi-Agent is the stronger model overall, scoring 46.2 to 32.5 on the Noometry Index. gpt-oss-20b costs 43× 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 . 16 shared benchmarks.

gpt-oss-20b OpenAI

32.5

Rank #255 Confirmed

Grok 4.20 Multi-Agent xAI

46.2

Rank #65 Confirmed

Summary

  • They share 16 benchmarks with published results for both. gpt-oss-20b scores higher in 1 category and Grok 4.20 Multi-Agent in 7 categories; 7 gaps are clear of the uncertainty.
  • The widest gap is in writing & preference, where Grok 4.20 Multi-Agent leads 64.0 to 35.5.
  • gpt-oss-20b is cheaper at $0.018 / $0.09 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-20b has downloadable open weights; the other is API-only.

Side by side

gpt-oss-20b and Grok 4.20 Multi-Agent specifications
gpt-oss-20bGrok 4.20 Multi-Agent
ProviderOpenAIxAI
Noometry Index32.546.2
Released2025-08-052026-03-09
WeightsOpenProprietary
Context window131K1M
Max output16K30K
Input $ / M tokens$0.018$1.25
Output $ / M tokens$0.09$2.50
Results tracked3420

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Category by category

Coding Grok 4.20 Multi-Agent leads

gpt-oss-20b: 37.6 (#192), Grok 4.20 Multi-Agent: 43.0 (#92)

Coding benchmarks
Benchmarkgpt-oss-20bGrok 4.20 Multi-Agent
LMArena Coding13061457
SciCode34.4%—
WeirdML40.9%—
ALE-Bench566.05—

Agentic & Tool Use Not comparable

gpt-oss-20b: 9.3 (#154), Grok 4.20 Multi-Agent: —

Agentic & Tool Use benchmarks
Benchmarkgpt-oss-20bGrok 4.20 Multi-Agent
Terminal-Bench3.4%—
LMArena Search—1204

Reasoning Grok 4.20 Multi-Agent leads

gpt-oss-20b: 19.3 (#261), Grok 4.20 Multi-Agent: 43.9 (#48)

Reasoning benchmarks
Benchmarkgpt-oss-20bGrok 4.20 Multi-Agent
LMArena Hard Prompts12741448
Kagi LLM Benchmark53.2%—
NYT Connections (extended)—89.6%
CritPt1.4%—
Chess Puzzles4%—
DTBench68%—
LMCA14.5%—
Epoch Capabilities Index137.82—

Math Too close to call

gpt-oss-20b: 39.4 (#103), Grok 4.20 Multi-Agent: 39.4 (#104)

Math benchmarks
Benchmarkgpt-oss-20bGrok 4.20 Multi-Agent
LMArena Math13171442
OTIS Mock AIME 2024-202565.3%—
Omni-MATH56.5%—

Knowledge Grok 4.20 Multi-Agent leads

gpt-oss-20b: 34.6 (#195), Grok 4.20 Multi-Agent: 40.4 (#119)

Knowledge benchmarks
Benchmarkgpt-oss-20bGrok 4.20 Multi-Agent
LMArena Expert12581445
GPQA Diamond60.8%—
MMLU-Pro74%—
GPQA (HELM)59.4%—

Multimodal Not comparable

gpt-oss-20b: —, Grok 4.20 Multi-Agent: 40.5 (#48)

Multimodal benchmarks
Benchmarkgpt-oss-20bGrok 4.20 Multi-Agent
LMArena Vision—1259

Multilingual Grok 4.20 Multi-Agent leads

gpt-oss-20b: 42.2 (#197), Grok 4.20 Multi-Agent: 54.4 (#43)

Multilingual benchmarks
Benchmarkgpt-oss-20bGrok 4.20 Multi-Agent
LMArena Non-English12681440
LMArena Chinese13141475
LMArena German12551456
LMArena Japanese12441405
LMArena Korean12361416
LMArena Russian12781457
LMArena Spanish12671447
LMArena French—1466

Instruction Following Grok 4.20 Multi-Agent leads

gpt-oss-20b: 61.8 (#240), Grok 4.20 Multi-Agent: 74.8 (#84)

Instruction Following benchmarks
Benchmarkgpt-oss-20bGrok 4.20 Multi-Agent
LMArena Instruction Following12361420
IFEval73.2%—

Long Context Grok 4.20 Multi-Agent leads

gpt-oss-20b: 37.9 (#209), Grok 4.20 Multi-Agent: 43.7 (#88)

Long Context benchmarks
Benchmarkgpt-oss-20bGrok 4.20 Multi-Agent
LMArena Longer Query12501431

Writing & Preference Grok 4.20 Multi-Agent leads

gpt-oss-20b: 35.5 (#265), Grok 4.20 Multi-Agent: 64.0 (#59)

Writing & Preference benchmarks
Benchmarkgpt-oss-20bGrok 4.20 Multi-Agent
LMArena Text12871450
LMArena Creative Writing12011436
LMArena Multi-Turn12681452
EQ-Bench Creative Writing666—
WildBench73.7%—

Frequently asked questions

Is gpt-oss-20b better than Grok 4.20 Multi-Agent?

Grok 4.20 Multi-Agent is the stronger model overall, scoring 46.2 to 32.5 on the Noometry Index. gpt-oss-20b costs 43× 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-20b or Grok 4.20 Multi-Agent?

gpt-oss-20b is cheaper. It lists at $0.018 per million input tokens and $0.09 per million output tokens; Grok 4.20 Multi-Agent lists at $1.25 and $2.50.

Is gpt-oss-20b or Grok 4.20 Multi-Agent better for coding?

Grok 4.20 Multi-Agent scores higher on coding benchmarks: 43.0 versus 37.6 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-20b and Grok 4.20 Multi-Agent share?

16 benchmarks have published results for both models. gpt-oss-20b has 34 scored results on Noometry and Grok 4.20 Multi-Agent has 20.

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