GPT-OSS 120B vs Grok 4.20 Beta

Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.

Benchmark data for one or both models is coming soon. This page currently shows metadata and pricing where BenchLM has it, and score-level comparisons will populate as public benchmark results land.

BenchLM does not have sourced benchmark coverage for Grok 4.20 Beta yet. This comparison is currently limited to metadata such as context window, reasoning mode, and pricing where available.

Grok 4.20 Beta has the larger context window at 2M, compared with 128K for GPT-OSS 120B.

Quick Verdict

Benchmark data for GPT-OSS 120B and Grok 4.20 Beta is coming soon on BenchLM.

Agentic

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

43
Terminal-Bench 2.0
Coming soon
50
BrowseComp
Coming soon
43
OSWorld-Verified
Coming soon

Coding

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

43
HumanEval
Coming soon
29
SWE-bench Verified
Coming soon
25
LiveCodeBench
Coming soon
31
SWE-bench Pro
Coming soon

Multimodal & Grounded

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

42
MMMU-Pro
Coming soon
57
OfficeQA Pro
Coming soon

Reasoning

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

49
SimpleQA
Coming soon
47
MuSR
Coming soon
73
BBH
Coming soon
58
LongBench v2
Coming soon
59
MRCRv2
Coming soon

Knowledge

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

51
MMLU
Coming soon
50
GPQA
Coming soon
48
SuperGPQA
Coming soon
46
OpenBookQA
Coming soon
63
MMLU-Pro
Coming soon
5
HLE
Coming soon
49
FrontierScience
Coming soon

Instruction Following

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

79
IFEval
Coming soon

Multilingual

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

72
MGSM
Coming soon
70
MMLU-ProX
Coming soon

Mathematics

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

51
AIME 2023
Coming soon
53
AIME 2024
Coming soon
52
AIME 2025
Coming soon
47
HMMT Feb 2023
Coming soon
49
HMMT Feb 2024
Coming soon
48
HMMT Feb 2025
Coming soon
50
BRUMO 2025
Coming soon
71
MATH-500
Coming soon

Frequently Asked Questions

Can I compare GPT-OSS 120B and Grok 4.20 Beta on BenchLM yet?

Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.

Why does this comparison show “coming soon”?

BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.

What data is available for GPT-OSS 120B and Grok 4.20 Beta today?

Grok 4.20 Beta: $2.00 input / $6.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.

Last updated: March 12, 2026

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