Model comparison

DeepSeek-V3.1 vs GPT-5 Nano

DeepSeek-V3.1 is the stronger model overall, scoring 42.2 to 33.4 on the Noometry Index. GPT-5 Nano costs 3.1× less per token, which makes it the better buy when DeepSeek-V3.1's lead doesn't matter for your workload.

Last verified . 24 shared benchmarks.

DeepSeek-V3.1 DeepSeek

42.2

Rank #106 Confirmed

GPT-5 Nano OpenAI

33.4

Rank #234 Confirmed

Summary

  • They share 24 benchmarks with published results for both. DeepSeek-V3.1 scores higher in 7 categories and GPT-5 Nano in 1 category; 8 gaps are clear of the uncertainty.
  • The widest gap is in writing & preference, where DeepSeek-V3.1 leads 60.5 to 39.4.
  • The biggest single-benchmark swing is DTBench: 82.7% for DeepSeek-V3.1 and 62.7% for GPT-5 Nano.
  • GPT-5 Nano is cheaper at $0.05 / $0.40 per million input/output tokens, against $0.25 / $0.95 for DeepSeek-V3.1.
  • GPT-5 Nano accepts more context: 400K tokens versus 164K.
  • DeepSeek-V3.1 has downloadable open weights; the other is API-only.

Side by side

DeepSeek-V3.1 and GPT-5 Nano specifications
DeepSeek-V3.1GPT-5 Nano
ProviderDeepSeekOpenAI
Noometry Index42.233.4
Released2025-08-212025-08-07
WeightsOpenProprietary
Context window164K400K
Max output8K128K
Input $ / M tokens$0.25$0.05
Output $ / M tokens$0.95$0.40
Results tracked2748

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Category by category

Coding DeepSeek-V3.1 leads

DeepSeek-V3.1: 39.8 (#140), GPT-5 Nano: 33.3 (#248)

Coding benchmarks
BenchmarkDeepSeek-V3.1GPT-5 Nano
WeirdML38.4%38.1%
LMArena Coding14171351
SWE-bench Verified (bash only)—34.8%
ALE-Bench—718.67

Agentic & Tool Use Not comparable

DeepSeek-V3.1: —, GPT-5 Nano: 25.6 (#99)

Agentic & Tool Use benchmarks
BenchmarkDeepSeek-V3.1GPT-5 Nano
Terminal-Bench—21.8%
Berkeley Function Calling Leaderboard—51.5%

Reasoning DeepSeek-V3.1 leads

DeepSeek-V3.1: 27.3 (#109), GPT-5 Nano: 16.4 (#291)

Reasoning benchmarks
BenchmarkDeepSeek-V3.1GPT-5 Nano
Kagi LLM Benchmark53.2%62.2%
LMArena Hard Prompts14171329
DTBench82.7%62.7%
LMCA24.3%7.9%
Epoch Capabilities Index139.92139.39
ForecastBench5859.1
ARC-AGI-2—2.6%
SimpleBench40%—
ARC-AGI-1—20.7%
Chess Puzzles—27%
Mystery Game Puzzles—9%

Math DeepSeek-V3.1 leads

DeepSeek-V3.1: 36.1 (#125), GPT-5 Nano: 29.1 (#221)

Math benchmarks
BenchmarkDeepSeek-V3.1GPT-5 Nano
LMArena Math14201318
FrontierMath (Tiers 1-3)—20%
FrontierMath Tier 4—2.4%
OTIS Mock AIME 2024-2025—81.1%
ProofBench—12%
Omni-MATH—54.6%
MATH Level 5—95.2%
FrontierMath (Feb 2025 set)—8.3%
FrontierMath Tier 4 (v1)—2.1%

Knowledge DeepSeek-V3.1 leads

DeepSeek-V3.1: 43.0 (#86), GPT-5 Nano: 35.8 (#166)

Knowledge benchmarks
BenchmarkDeepSeek-V3.1GPT-5 Nano
Vectara Hallucination Rate5.5%10.5%
LMArena Expert14031321
GPQA Diamond—69.4%
SimpleQA Verified—11.7%
MMLU-Pro—77.8%
GPQA (HELM)—67.9%

Multimodal Not comparable

DeepSeek-V3.1: —, GPT-5 Nano: 30.7 (#102)

Multimodal benchmarks
BenchmarkDeepSeek-V3.1GPT-5 Nano
LMArena Vision—1159
VPCT—37.2%

Multilingual DeepSeek-V3.1 leads

DeepSeek-V3.1: 51.8 (#100), GPT-5 Nano: 45.5 (#167)

Multilingual benchmarks
BenchmarkDeepSeek-V3.1GPT-5 Nano
LMArena Non-English14001313
LMArena Chinese14701355
LMArena German14121329
LMArena Korean13371269
LMArena Russian14051296
LMArena Spanish14291360
LMArena French1447—
LMArena Japanese1374—

Instruction Following GPT-5 Nano leads

DeepSeek-V3.1: 74.1 (#105), GPT-5 Nano: 75.2 (#72)

Instruction Following benchmarks
BenchmarkDeepSeek-V3.1GPT-5 Nano
LMArena Instruction Following14001306
IFEval—93.2%

Long Context DeepSeek-V3.1 leads

DeepSeek-V3.1: 36.3 (#227), GPT-5 Nano: 31.3 (#275)

Long Context benchmarks
BenchmarkDeepSeek-V3.1GPT-5 Nano
Fiction.LiveBench52.8%44.4%
LMArena Longer Query14221313

Writing & Preference DeepSeek-V3.1 leads

DeepSeek-V3.1: 60.5 (#93), GPT-5 Nano: 39.4 (#244)

Writing & Preference benchmarks
BenchmarkDeepSeek-V3.1GPT-5 Nano
LMArena Text14201320
LMArena Creative Writing14011250
EQ-Bench Creative Writing1436705
LMArena Multi-Turn14081311
WildBench—80.6%

Frequently asked questions

Is DeepSeek-V3.1 better than GPT-5 Nano?

DeepSeek-V3.1 is the stronger model overall, scoring 42.2 to 33.4 on the Noometry Index. GPT-5 Nano costs 3.1× less per token, which makes it the better buy when DeepSeek-V3.1's lead doesn't matter for your workload.

Which is cheaper, DeepSeek-V3.1 or GPT-5 Nano?

GPT-5 Nano is cheaper. It lists at $0.05 per million input tokens and $0.40 per million output tokens; DeepSeek-V3.1 lists at $0.25 and $0.95.

Is DeepSeek-V3.1 or GPT-5 Nano better for coding?

DeepSeek-V3.1 scores higher on coding benchmarks: 39.8 versus 33.3 in the Noometry coding category.

Which has the bigger context window?

GPT-5 Nano does, with 400K tokens against 164K.

How many benchmarks do DeepSeek-V3.1 and GPT-5 Nano share?

24 benchmarks have published results for both models. DeepSeek-V3.1 has 27 scored results on Noometry and GPT-5 Nano has 48.

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