Model comparison

DeepSeek V4.1 Flash vs GPT-5

DeepSeek V4.1 Flash is the stronger model overall, scoring 52.8 to 50.9 on the Noometry Index.

Last verified . 32 shared benchmarks.

DeepSeek V4.1 Flash DeepSeek

52.8

Rank #38 Confirmed

GPT-5 OpenAI

50.9

Rank #45 Confirmed

Summary

  • They share 32 benchmarks with published results for both. DeepSeek V4.1 Flash scores higher in 7 categories and GPT-5 in 3 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in long context, where GPT-5 leads 69.5 to 45.2.
  • The biggest single-benchmark swing is ProofBench: 54% for DeepSeek V4.1 Flash and 18% for GPT-5.
  • DeepSeek V4.1 Flash is cheaper at $0.15 / $0.60 per million input/output tokens, against $1.25 / $10 for GPT-5.
  • DeepSeek V4.1 Flash accepts more context: 1M tokens versus 400K.
  • DeepSeek V4.1 Flash has downloadable open weights; the other is API-only.

Side by side

DeepSeek V4.1 Flash and GPT-5 specifications
DeepSeek V4.1 FlashGPT-5
ProviderDeepSeekOpenAI
Noometry Index52.850.9
Released2026-09-092025-08-07
WeightsOpenProprietary
Context window1M400K
Max output393K128K
Input $ / M tokens$0.15$1.25
Output $ / M tokens$0.60$10
Results tracked3769

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Category by category

Coding DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 52.9 (#32), GPT-5: 50.3 (#47)

Coding benchmarks
BenchmarkDeepSeek V4.1 FlashGPT-5
LMArena WebDev16191418
SciCode51.9%42.9%
LMArena Coding15061436
ALE-Bench1,0921,162
SWE-bench Verified—73.6%
SWE-bench Verified (bash only)—65%
Aider Polyglot—88%
GSO—6.9%
WeirdML—60.7%
AlgoTune—1.67

Agentic & Tool Use GPT-5 leads

DeepSeek V4.1 Flash: 31.2 (#69), GPT-5: 33.1 (#56)

Agentic & Tool Use benchmarks
BenchmarkDeepSeek V4.1 FlashGPT-5
Terminal-Bench—49.6%
APEX-Agents39.5%—
GDPval—34.8%
Remote Labor Index—1.7%
DeepResearch Bench—49.6%
BALROG—32.8%
GDP.pdf19.8%—
LMArena Search—1133
METR Time Horizons—69.6%

Reasoning DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 50.2 (#36), GPT-5: 38.3 (#64)

Reasoning benchmarks
BenchmarkDeepSeek V4.1 FlashGPT-5
CritPt14.3%12.6%
LMArena Hard Prompts14831416
Mystery Game Puzzles43%23%
DTBench89.9%90.7%
LMCA47%40%
Epoch Capabilities Index154.9150
ARC-AGI-2—9.9%
SimpleBench—56.7%
Kagi LLM Benchmark—72.7%
NYT Connections (extended)89.6%—
ARC-AGI-1—65.7%
Chess Puzzles—37%
EnigmaEval—10.5%
EBR-Bench—12.7%
Surface Evolver Bench46.3%—
ForecastBench—61.4

Math DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 66.7 (#25), GPT-5: 55.0 (#44)

Math benchmarks
BenchmarkDeepSeek V4.1 FlashGPT-5
FrontierMath (Tiers 1-3)67.4%55.4%
FrontierMath Tier 426.8%22%
OTIS Mock AIME 2024-202598.3%91.4%
ProofBench54%18%
LMArena Math14771407
Omni-MATH—64.7%
MATH Level 5—98.1%
FrontierMath (Feb 2025 set)—32.4%
FrontierMath Tier 4 (v1)—12.5%

Knowledge DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 57.9 (#38), GPT-5: 56.6 (#43)

Knowledge benchmarks
BenchmarkDeepSeek V4.1 FlashGPT-5
GPQA Diamond89.8%86.2%
LMArena Expert15061419
Humanity's Last Exam—25.3%
SimpleQA Verified—50.1%
MMLU-Pro—86.3%
Confabulations—10.3%
Vectara Hallucination Rate—14.7%
GPQA (HELM)—79.2%

Multimodal GPT-5 leads

DeepSeek V4.1 Flash: 39.1 (#61), GPT-5: 46.8 (#13)

Multimodal benchmarks
BenchmarkDeepSeek V4.1 FlashGPT-5
LMArena Vision12771232
GeoBench—81%
VPCT—66%
Furniture Assembly34.2%—

Multilingual DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 55.0 (#35), GPT-5: 51.4 (#110)

Multilingual benchmarks
BenchmarkDeepSeek V4.1 FlashGPT-5
LMArena Non-English14481397
LMArena Chinese14971422
LMArena French14521410
LMArena German14841416
LMArena Japanese14121409
LMArena Korean14521360
LMArena Russian14711406
LMArena Spanish14591399

Instruction Following DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 77.3 (#26), GPT-5: 73.8 (#113)

Instruction Following benchmarks
BenchmarkDeepSeek V4.1 FlashGPT-5
LMArena Instruction Following14741388
IFEval—87.5%

Long Context GPT-5 leads

DeepSeek V4.1 Flash: 45.2 (#47), GPT-5: 69.5 (#2)

Long Context benchmarks
BenchmarkDeepSeek V4.1 FlashGPT-5
LMArena Longer Query14751399
Fiction.LiveBench—97.2%

Writing & Preference DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 65.4 (#48), GPT-5: 63.4 (#65)

Writing & Preference benchmarks
BenchmarkDeepSeek V4.1 FlashGPT-5
LMArena Text14621406
LMArena Creative Writing14351365
EQ-Bench Creative Writing15401627
LMArena Multi-Turn14571426
Short-Story Creative Writing—86%
WildBench—85.7%

Frequently asked questions

Is DeepSeek V4.1 Flash better than GPT-5?

DeepSeek V4.1 Flash is the stronger model overall, scoring 52.8 to 50.9 on the Noometry Index.

Which is cheaper, DeepSeek V4.1 Flash or GPT-5?

DeepSeek V4.1 Flash is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; GPT-5 lists at $1.25 and $10.

Is DeepSeek V4.1 Flash or GPT-5 better for coding?

DeepSeek V4.1 Flash scores higher on coding benchmarks: 52.9 versus 50.3 in the Noometry coding category.

Which has the bigger context window?

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

How many benchmarks do DeepSeek V4.1 Flash and GPT-5 share?

32 benchmarks have published results for both models. DeepSeek V4.1 Flash has 37 scored results on Noometry and GPT-5 has 69.

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