Model comparison

DeepSeek V4 Flash vs GPT-5.6 Luna

DeepSeek V4 Flash and GPT-5.6 Luna score almost the same on the Noometry Index (53.6 vs 54.6), so choose on price, context window or the category you care about most.

Last verified . 40 shared benchmarks.

DeepSeek V4 Flash DeepSeek

53.6

Rank #35 Confirmed

GPT-5.6 Luna OpenAI

54.6

Rank #30 Confirmed

Summary

  • They share 40 benchmarks with published results for both. DeepSeek V4 Flash scores higher in 2 categories and GPT-5.6 Luna in 6 categories; 5 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.6 Luna leads 77.7 to 60.3.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 24.4% for DeepSeek V4 Flash and 61% for GPT-5.6 Luna.
  • DeepSeek V4 Flash is cheaper at $0.15 / $0.60 per million input/output tokens, against $0.20 / $1.20 for GPT-5.6 Luna.
  • GPT-5.6 Luna accepts more context: 1.05M tokens versus 1M.
  • DeepSeek V4 Flash has downloadable open weights; the other is API-only.

Side by side

DeepSeek V4 Flash and GPT-5.6 Luna specifications
DeepSeek V4 FlashGPT-5.6 Luna
ProviderDeepSeekOpenAI
Noometry Index53.654.6
Released2026-04-242026-07-09
WeightsOpenProprietary
Context window1M1.05M
Max output393K128K
Input $ / M tokens$0.15$0.20
Output $ / M tokens$0.60$1.20
Results tracked4152

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Category by category

Coding GPT-5.6 Luna leads

DeepSeek V4 Flash: 47.9 (#59), GPT-5.6 Luna: 54.5 (#28)

Coding benchmarks
BenchmarkDeepSeek V4 FlashGPT-5.6 Luna
FrontierCode18.8%39.8%
LMArena WebDev15821519
SciCode49.9%53.6%
WeirdML63%60.9%
LMArena Coding14571466
ALE-Bench1,3061,667
DeepSWE—67.2%
CursorBench—35.9%

Agentic & Tool Use Not comparable

DeepSeek V4 Flash: —, GPT-5.6 Luna: 34.4 (#45)

Agentic & Tool Use benchmarks
BenchmarkDeepSeek V4 FlashGPT-5.6 Luna
APEX-Agents—43%
BALROG—45.6%
GDP.pdf—22.7%
Vending-Bench 2—4,095

Reasoning DeepSeek V4 Flash leads

DeepSeek V4 Flash: 53.7 (#30), GPT-5.6 Luna: 47.6 (#43)

Reasoning benchmarks
BenchmarkDeepSeek V4 FlashGPT-5.6 Luna
ARC-AGI-261.4%59.5%
SimpleBench61.1%46.8%
Kagi LLM Benchmark52.2%49.1%
NYT Connections (extended)89.6%69.4%
ARC-AGI-189%88%
CritPt16.6%20.6%
Chess Puzzles33%40%
LMArena Hard Prompts14441451
Mystery Game Puzzles34%21%
DTBench90.9%89.1%
LMCA41.7%48.5%
Epoch Capabilities Index154.49156.39
Surface Evolver Bench—61.9%

Math GPT-5.6 Luna leads

DeepSeek V4 Flash: 60.3 (#37), GPT-5.6 Luna: 77.7 (#14)

Math benchmarks
BenchmarkDeepSeek V4 FlashGPT-5.6 Luna
FrontierMath (Tiers 1-3)57.5%82.1%
FrontierMath Tier 424.4%61%
OTIS Mock AIME 2024-202594.4%98.3%
ProofBench56%60%
LMArena Math14271458
MathArena Final-Answer Competitions76.5%—

Knowledge GPT-5.6 Luna leads

DeepSeek V4 Flash: 55.4 (#48), GPT-5.6 Luna: 58.5 (#34)

Knowledge benchmarks
BenchmarkDeepSeek V4 FlashGPT-5.6 Luna
GPQA Diamond91%91.6%
SimpleQA Verified33.6%41%
LMArena Expert14411478

Multimodal Not comparable

DeepSeek V4 Flash: —, GPT-5.6 Luna: 42.7 (#28)

Multimodal benchmarks
BenchmarkDeepSeek V4 FlashGPT-5.6 Luna
LMArena Vision—1258
Blueprint-Bench 2—22.6%
Furniture Assembly—42.5%
LMArena Document—1457

Multilingual Too close to call

DeepSeek V4 Flash: 53.0 (#72), GPT-5.6 Luna: 52.8 (#78)

Multilingual benchmarks
BenchmarkDeepSeek V4 FlashGPT-5.6 Luna
LMArena Non-English14201417
LMArena Chinese14681470
LMArena French14391456
LMArena German14181454
LMArena Japanese14061411
LMArena Korean13841415
LMArena Russian14281428
LMArena Spanish14361448

Instruction Following Too close to call

DeepSeek V4 Flash: 74.9 (#81), GPT-5.6 Luna: 75.6 (#57)

Instruction Following benchmarks
BenchmarkDeepSeek V4 FlashGPT-5.6 Luna
LMArena Instruction Following14211437

Long Context Too close to call

DeepSeek V4 Flash: 43.8 (#85), GPT-5.6 Luna: 43.9 (#82)

Long Context benchmarks
BenchmarkDeepSeek V4 FlashGPT-5.6 Luna
LMArena Longer Query14341436

Writing & Preference GPT-5.6 Luna leads

DeepSeek V4 Flash: 63.8 (#61), GPT-5.6 Luna: 68.0 (#29)

Writing & Preference benchmarks
BenchmarkDeepSeek V4 FlashGPT-5.6 Luna
LMArena Text14321431
LMArena Creative Writing14031396
EQ-Bench Creative Writing15591829
LMArena Multi-Turn14491434
EQ-Bench 4—1156

Frequently asked questions

Is DeepSeek V4 Flash better than GPT-5.6 Luna?

DeepSeek V4 Flash and GPT-5.6 Luna score almost the same on the Noometry Index (53.6 vs 54.6), so choose on price, context window or the category you care about most.

Which is cheaper, DeepSeek V4 Flash or GPT-5.6 Luna?

DeepSeek V4 Flash is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; GPT-5.6 Luna lists at $0.20 and $1.20.

Is DeepSeek V4 Flash or GPT-5.6 Luna better for coding?

GPT-5.6 Luna scores higher on coding benchmarks: 54.5 versus 47.9 in the Noometry coding category.

Which has the bigger context window?

GPT-5.6 Luna does, with 1.05M tokens against 1M.

How many benchmarks do DeepSeek V4 Flash and GPT-5.6 Luna share?

40 benchmarks have published results for both models. DeepSeek V4 Flash has 41 scored results on Noometry and GPT-5.6 Luna has 52.

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