Model comparison

DeepSeek V4 Flash vs GPT-5 Nano

DeepSeek V4 Flash is the stronger model overall, scoring 53.6 to 33.5 on the Noometry Index. GPT-5 Nano costs 1.9× less per token, which makes it the better buy when DeepSeek V4 Flash's lead doesn't matter for your workload.

Last verified . 33 shared benchmarks.

DeepSeek V4 Flash DeepSeek

53.6

Rank #35 Confirmed

GPT-5 Nano OpenAI

33.5

Rank #241 Confirmed

Summary

  • They share 33 benchmarks with published results for both. DeepSeek V4 Flash scores higher in 7 categories and GPT-5 Nano in 1 category; 7 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where DeepSeek V4 Flash leads 53.7 to 16.3.
  • The biggest single-benchmark swing is ARC-AGI-1: 89% for DeepSeek V4 Flash and 20.7% for GPT-5 Nano.
  • GPT-5 Nano is cheaper at $0.05 / $0.40 per million input/output tokens, against $0.15 / $0.60 for DeepSeek V4 Flash.
  • DeepSeek V4 Flash accepts more context: 1M tokens versus 400K.
  • DeepSeek V4 Flash has downloadable open weights; the other is API-only.

Side by side

DeepSeek V4 Flash and GPT-5 Nano specifications
DeepSeek V4 FlashGPT-5 Nano
ProviderDeepSeekOpenAI
Noometry Index53.633.5
Released2026-04-242025-08-07
WeightsOpenProprietary
Context window1M400K
Max output393K128K
Input $ / M tokens$0.15$0.05
Output $ / M tokens$0.60$0.40
Results tracked4149

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Category by category

Coding DeepSeek V4 Flash leads

DeepSeek V4 Flash: 47.9 (#59), GPT-5 Nano: 33.6 (#254)

Coding benchmarks
BenchmarkDeepSeek V4 FlashGPT-5 Nano
WeirdML63%38.1%
LMArena Coding14571351
ALE-Bench1,306718.67
FrontierCode18.8%—
SWE-bench Verified (bash only)—34.8%
LMArena WebDev1582—
SciCode49.9%—

Agentic & Tool Use Not comparable

DeepSeek V4 Flash: —, GPT-5 Nano: 25.8 (#106)

Agentic & Tool Use benchmarks
BenchmarkDeepSeek V4 FlashGPT-5 Nano
Terminal-Bench—21.8%
Berkeley Function Calling Leaderboard—51.5%

Reasoning DeepSeek V4 Flash leads

DeepSeek V4 Flash: 53.7 (#30), GPT-5 Nano: 16.3 (#306)

Reasoning benchmarks
BenchmarkDeepSeek V4 FlashGPT-5 Nano
ARC-AGI-261.4%2.6%
Kagi LLM Benchmark52.2%62.2%
ARC-AGI-189%20.7%
Chess Puzzles33%27%
LMArena Hard Prompts14441328
Mystery Game Puzzles34%9%
DTBench90.9%62.7%
LMCA41.7%7.9%
Epoch Capabilities Index154.49139.38
SimpleBench61.1%—
NYT Connections (extended)89.6%—
CritPt16.6%—
ForecastBench—59.1

Math DeepSeek V4 Flash leads

DeepSeek V4 Flash: 60.3 (#37), GPT-5 Nano: 29.4 (#241)

Knowledge DeepSeek V4 Flash leads

DeepSeek V4 Flash: 55.4 (#48), GPT-5 Nano: 35.9 (#178)

Knowledge benchmarks
BenchmarkDeepSeek V4 FlashGPT-5 Nano
GPQA Diamond91%69.4%
SimpleQA Verified33.6%11.7%
LMArena Expert14411321
MMLU-Pro—77.8%
Vectara Hallucination Rate—10.5%
GPQA (HELM)—67.9%

Multimodal Not comparable

DeepSeek V4 Flash: —, GPT-5 Nano: 31.3 (#108)

Multimodal benchmarks
BenchmarkDeepSeek V4 FlashGPT-5 Nano
LMArena Vision—1159
VPCT—37.2%

Multilingual DeepSeek V4 Flash leads

DeepSeek V4 Flash: 53.0 (#72), GPT-5 Nano: 45.3 (#172)

Multilingual benchmarks
BenchmarkDeepSeek V4 FlashGPT-5 Nano
LMArena Non-English14201313
LMArena Chinese14681356
LMArena German14181327
LMArena Japanese14061226
LMArena Korean13841269
LMArena Russian14281296
LMArena Spanish14361360
LMArena French1439—

Instruction Following Too close to call

DeepSeek V4 Flash: 74.9 (#81), GPT-5 Nano: 75.0 (#79)

Instruction Following benchmarks
BenchmarkDeepSeek V4 FlashGPT-5 Nano
LMArena Instruction Following14211306
IFEval—93.2%

Long Context DeepSeek V4 Flash leads

DeepSeek V4 Flash: 43.8 (#85), GPT-5 Nano: 31.3 (#281)

Long Context benchmarks
BenchmarkDeepSeek V4 FlashGPT-5 Nano
LMArena Longer Query14341312
Fiction.LiveBench—44.4%

Writing & Preference DeepSeek V4 Flash leads

DeepSeek V4 Flash: 63.8 (#61), GPT-5 Nano: 39.1 (#249)

Writing & Preference benchmarks
BenchmarkDeepSeek V4 FlashGPT-5 Nano
LMArena Text14321320
LMArena Creative Writing14031249
EQ-Bench Creative Writing1559705
LMArena Multi-Turn14491311
WildBench—80.6%

Frequently asked questions

Is DeepSeek V4 Flash better than GPT-5 Nano?

DeepSeek V4 Flash is the stronger model overall, scoring 53.6 to 33.5 on the Noometry Index. GPT-5 Nano costs 1.9× less per token, which makes it the better buy when DeepSeek V4 Flash's lead doesn't matter for your workload.

Which is cheaper, DeepSeek V4 Flash 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 V4 Flash lists at $0.15 and $0.60.

Is DeepSeek V4 Flash or GPT-5 Nano better for coding?

DeepSeek V4 Flash scores higher on coding benchmarks: 47.9 versus 33.6 in the Noometry coding category.

Which has the bigger context window?

DeepSeek V4 Flash does, with 1M tokens against 400K.

How many benchmarks do DeepSeek V4 Flash and GPT-5 Nano share?

33 benchmarks have published results for both models. DeepSeek V4 Flash has 41 scored results on Noometry and GPT-5 Nano has 49.

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