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Model comparison

GPT-4.1 vs GPT-OSS 20B

Data verified

Head-to-head evidence from 12 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

OpenAI
50.44/100
Margin
8.5pts
← winning
41.95/100
0 category wins0 category wins

Public leaderboard positions: GPT-4.1 #111 (Supported); GPT-OSS 20B #167 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-4.1 and GPT-OSS 20B share 12 comparable benchmark results. 0 of 8 categories are comparable. 8 results are unique to GPT-4.1; 6 to GPT-OSS 20B.

Updated July 24, 2026
Shared results
12
GPT-4.1 only
8
GPT-OSS 20B only
6
Comparable categories
0 / 8

Benchmark data for GPT-4.1 and GPT-OSS 20B is coming soon on BenchLM.

Confidence note. This is a partial-evidence comparison with 12 shared benchmark results across 6 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.

GPT-4.1 is priced at $2.00 input / $8.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for GPT-OSS 20B. GPT-4.1 has the larger context window at 1M, compared with 128K for GPT-OSS 20B.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for GPT-4.1 and GPT-OSS 20B
CategoryGPT-4.1ΔGPT-OSS 20B
CodingGPT-4.154.6MarginNo overlapGPT-OSS 20BNot measured
KnowledgeGPT-4.166.3MarginNo overlapGPT-OSS 20BNot measured
MathGPT-4.14.1MarginNo overlapGPT-OSS 20BNot measured
Inst. FollowingGPT-4.187.4MarginNo overlapGPT-OSS 20BNot measured

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricGPT-4.1GPT-OSS 20BComparison
Input / output priceUSD per 1M tokensGPT-4.1$2 input / $8 outputGPT-OSS 20B$0 input / $0 outputGPT-OSS 20B has the lower combined listed price.
Generation speedtokens per secondGPT-4.1108 tok/sGPT-OSS 20B313 tok/sGPT-OSS 20B has the higher measured throughput.
First-answer latencyseconds to first tokenGPT-4.11.02 sGPT-OSS 20B0.65 sGPT-OSS 20B reaches the first token sooner.
Context windowmaximum listed tokensGPT-4.11MGPT-OSS 20B128KGPT-4.1 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkGPT-4.1GPT-OSS 20BResult
τ²-bench resultsSource 47.1%60.2%GPT-OSS 20B leads
Gert LabsSource 25.65%Not comparable
AA Agentic IndexSource 3.1%Not comparable
APEX-Agents-AASource 0.7%Not comparable
GDPval-AASource 3.4%Not comparable
GDPval-AASource 567Not comparable
Coding
BenchmarkGPT-4.1GPT-OSS 20BResult
SWE-bench VerifiedSource 54.6%Not comparable
AA-SciCodeSource 38.1%34.4%GPT-4.1 leads
React Native EvalsSource 71%Not comparable
AA Coding IndexSource 20.7%Not comparable
Reasoning
BenchmarkGPT-4.1GPT-OSS 20BResult
AA-LCRSource 61.0%30.7%GPT-4.1 leads
CritPtSource 0.0%1.4%GPT-OSS 20B leads
Knowledge
BenchmarkGPT-4.1GPT-OSS 20BResult
MMLUSource 90.2%Not comparable
GPQASource 66.3%Not comparable
Artificial Analysis Intelligence IndexSource 19.4%14.9%GPT-4.1 leads
AA-GPQA DiamondSource 66.6%68.8%GPT-OSS 20B leads
AA-HLESource 4.6%9.8%GPT-OSS 20B leads
AA-Omniscience IndexSource -36.2%-63.9%GPT-4.1 leads
AA-Omniscience AccuracySource 24.2%15.5%GPT-4.1 leads
AA-Omniscience Hallucination RateSource 79.6%94.1%GPT-4.1 leads
Math
BenchmarkGPT-4.1GPT-OSS 20BResult
FrontierMath v2 (Tiers 1-3)Source 5.517%Not comparable
FrontierMath v2 (Tier 4)Source 0.000%Not comparable
Multimodal
BenchmarkGPT-4.1GPT-OSS 20BResult
AA-MMMU-ProSource 61.2%Not comparable
Design Arena WebsiteSource 1068882GPT-4.1 leads
Inst. Following
BenchmarkGPT-4.1GPT-OSS 20BResult
IFEvalSource 87.4%Not comparable
AA-IFBenchSource 43.0%65.1%GPT-OSS 20B leads
Frequently Asked Questions (3)

Can I compare GPT-4.1 and GPT-OSS 20B 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-4.1 and GPT-OSS 20B today?

GPT-4.1: $2.00 input / $8.00 output per 1M tokens GPT-OSS 20B: $0.00 input / $0.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.

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Last updated: July 24, 2026