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Model comparison

GPT-OSS 20B vs Kimi K2.5

Data verified

Head-to-head evidence from 18 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

42.74/100
Margin
16.9pts
winning →
Kimi K2.5
Moonshot AI
59.66/100
0 category wins0 category wins

Public leaderboard positions: GPT-OSS 20B #159 (Supported); Kimi K2.5 #54 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-OSS 20B and Kimi K2.5 share 18 comparable benchmark results. 0 of 8 categories are comparable. 0 results are unique to GPT-OSS 20B; 45 to Kimi K2.5.

Updated July 20, 2026
Shared results
18
GPT-OSS 20B only
0
Kimi K2.5 only
45
Comparable categories
0 / 8

Benchmark data for GPT-OSS 20B and Kimi K2.5 is coming soon on BenchLM.

Confidence note. This is a partial-evidence comparison with 18 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.

Kimi K2.5 is priced at $0.60 input / $3.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for GPT-OSS 20B. Kimi K2.5 has the larger context window at 256K, 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-OSS 20B and Kimi K2.5
CategoryGPT-OSS 20BΔKimi K2.5
AgenticGPT-OSS 20BNot measuredMarginNo overlapKimi K2.555.0
CodingGPT-OSS 20BNot measuredMarginNo overlapKimi K2.559.4
ReasoningGPT-OSS 20BNot measuredMarginNo overlapKimi K2.561.0
KnowledgeGPT-OSS 20BNot measuredMarginNo overlapKimi K2.556.9
MathGPT-OSS 20BNot measuredMarginNo overlapKimi K2.560.6
MultilingualGPT-OSS 20BNot measuredMarginNo overlapKimi K2.582.3
MultimodalGPT-OSS 20BNot measuredMarginNo overlapKimi K2.578.5
Inst. FollowingGPT-OSS 20BNot measuredMarginNo overlapKimi K2.593.9

Operational comparison

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

MetricGPT-OSS 20BKimi K2.5Comparison
Input / output priceUSD per 1M tokensGPT-OSS 20B$0 input / $0 outputKimi K2.5$0.6 input / $3 outputGPT-OSS 20B has the lower combined listed price.
Generation speedtokens per secondGPT-OSS 20B313 tok/sKimi K2.545 tok/sGPT-OSS 20B has the higher measured throughput.
First-answer latencyseconds to first tokenGPT-OSS 20B0.65 sKimi K2.52.38 sGPT-OSS 20B reaches the first token sooner.
Context windowmaximum listed tokensGPT-OSS 20B128KKimi K2.5256KKimi K2.5 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkGPT-OSS 20BKimi K2.5Result
AA Agentic IndexSource 3.1%21.7%Kimi K2.5 leads
APEX-Agents-AASource 0.7%11.5%Kimi K2.5 leads
τ²-bench resultsSource 60.2%95.9%Kimi K2.5 leads
GDPval-AASource 3.0%25.4%Kimi K2.5 leads
GDPval-AASource 5591009Kimi K2.5 leads
Terminal-Bench 2.0Source —50.8%Not comparable
BrowseCompSource —60.6%Not comparable
Claw-EvalSource —52.3%Not comparable
QwenClawBenchSource —54.3%Not comparable
τ³-bench resultsSource —65.7%Not comparable
DeepSearchQASource —77.1%Not comparable
DeepPlanningSource —14.4%Not comparable
ToolathlonSource —27.8%Not comparable
MCP AtlasSource —29.5%Not comparable
MCP-TasksSource —59.1%Not comparable
WideResearchSource —72.7%Not comparable
Gert LabsSource —45.88%Not comparable
ResearchClawBenchSource —14.0%Not comparable
JobBenchSource —8.7%Not comparable
Coding
BenchmarkGPT-OSS 20BKimi K2.5Result
React Native EvalsSource 71%77.2%Kimi K2.5 leads
AA Coding IndexSource 20.7%46.8%Kimi K2.5 leads
AA-SciCodeSource 34.4%49.0%Kimi K2.5 leads
SWE-bench VerifiedSource —76.8%Not comparable
SWE-bench Verified*Source —70.8%Not comparable
LiveCodeBench v6Source —85.0%Not comparable
SWE-bench ProSource —50.7%Not comparable
SWE MultilingualSource —73%Not comparable
SWE-RebenchSource —58.5%Not comparable
SciCodeSource —48.7%Not comparable
Reasoning
BenchmarkGPT-OSS 20BKimi K2.5Result
AA-LCRSource 30.7%65.3%Kimi K2.5 leads
CritPtSource 1.4%3.1%Kimi K2.5 leads
LongBench v2Source —61%Not comparable
Knowledge
BenchmarkGPT-OSS 20BKimi K2.5Result
Artificial Analysis Intelligence IndexSource 14.9%35.4%Kimi K2.5 leads
AA-GPQA DiamondSource 68.8%87.9%Kimi K2.5 leads
AA-HLESource 9.8%29.4%Kimi K2.5 leads
AA-Omniscience IndexSource -63.9%-8.1%Kimi K2.5 leads
AA-Omniscience AccuracySource 15.5%34.3%Kimi K2.5 leads
AA-Omniscience Hallucination RateSource 94.1%64.6%Kimi K2.5 leads
GPQASource —87.6%Not comparable
GPQA-DSource —87.6%Not comparable
SuperGPQASource —69.2%Not comparable
MMLU-ProSource —87.1%Not comparable
MMLU-Pro (Arcee)Source —87.1%Not comparable
HLESource —30.1%Not comparable
Math
BenchmarkGPT-OSS 20BKimi K2.5Result
AIME 2025Source —96.1%Not comparable
AIME26Source —95.8%Not comparable
AIME25 (Arcee)Source —96.3%Not comparable
HMMT Feb 2025Source —95.4%Not comparable
HMMT Nov 2025Source —91.1%Not comparable
HMMT Feb 2026Source —87.1%Not comparable
MMAnswerBenchSource —81.8%Not comparable
FrontierMath v2 (Tiers 1-3)Source —27.900%Not comparable
FrontierMath v2 (Tier 4)Source —4.200%Not comparable
Multilingual
BenchmarkGPT-OSS 20BKimi K2.5Result
MMLU-ProXSource —82.3%Not comparable
NOVA-63Source —56.0%Not comparable
Multimodal
BenchmarkGPT-OSS 20BKimi K2.5Result
Design Arena WebsiteSource 8851282Kimi K2.5 leads
MMMU-ProSource —78.5%Not comparable
Video-MMESource —87.4%Not comparable
MMVUSource —80.4%Not comparable
VideoMMMUSource —86.6%Not comparable
AA-MMMU-ProSource —75.4%Not comparable
Inst. Following
BenchmarkGPT-OSS 20BKimi K2.5Result
AA-IFBenchSource 65.1%70.2%Kimi K2.5 leads
IFEvalSource —93.9%Not comparable
Frequently Asked Questions (3)

Can I compare GPT-OSS 20B and Kimi K2.5 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 20B and Kimi K2.5 today?

GPT-OSS 20B: $0.00 input / $0.00 output per 1M tokens Kimi K2.5: $0.60 input / $3.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.

Self-host vs API cost

Estimates at 50,000 req/day · 1000 tokens/req average.

GPT-OSS 20B
API / mo$0
Self-host / moNot listed
Break-even—
Proprietary model — self-hosting not applicable.
Kimi K2.5
API / mo$2,700
Self-host / mo$5,221
Break-even132M/day
Model the full break-even

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