Noometry

Model comparison

Claude Opus 4.5 vs DeepSeek V4.1 Flash

DeepSeek V4.1 Flash is the stronger model overall, scoring 52.8 to 50.5 on the Noometry Index.

Last verified . 31 shared benchmarks.

Claude Opus 4.5 Anthropic

50.5

Rank #47 Confirmed

DeepSeek V4.1 Flash DeepSeek

52.8

Rank #38 Confirmed

Summary

  • They share 31 benchmarks with published results for both. Claude Opus 4.5 scores higher in 5 categories and DeepSeek V4.1 Flash in 5 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where DeepSeek V4.1 Flash leads 66.7 to 38.6.
  • The biggest single-benchmark swing is NYT Connections (extended): 52.5% for Claude Opus 4.5 and 89.6% for DeepSeek V4.1 Flash.
  • DeepSeek V4.1 Flash is cheaper at $0.15 / $0.60 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.
  • DeepSeek V4.1 Flash accepts more context: 1M tokens versus 200K.
  • DeepSeek V4.1 Flash has downloadable open weights; the other is API-only.

Side by side

Claude Opus 4.5DeepSeek V4.1 Flash
ProviderAnthropicDeepSeek
Noometry Index50.552.8
Released2025-11-012026-09-09
WeightsProprietaryOpen
Context window200K1M
Max output64K393K
Input $ / M tokens$5$0.15
Output $ / M tokens$25$0.60
Results tracked6937

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Category by category

Coding Claude Opus 4.5 leads

Claude Opus 4.5: 54.8 (#27), DeepSeek V4.1 Flash: 52.9 (#32)

BenchmarkClaude Opus 4.5DeepSeek V4.1 Flash
LMArena WebDev14941619
LMArena Coding15041506
ALE-Bench1,0251,092
SWE-bench Verified76.7%—
SWE-bench Verified (bash only)76.8%—
SWE-bench Multilingual70.7%—
SciCode—51.9%
GSO26.5%—
WeirdML63.7%—
AlgoTune1.77—

Agentic & Tool Use Claude Opus 4.5 leads

Claude Opus 4.5: 47.3 (#12), DeepSeek V4.1 Flash: 31.2 (#69)

BenchmarkClaude Opus 4.5DeepSeek V4.1 Flash
Terminal-Bench63.1%—
APEX-Agents—39.5%
Berkeley Function Calling Leaderboard77.5%—
GDPval45.5%—
Remote Labor Index3.8%—
τ²-bench Airline84%—
τ²-bench Banking24.7%—
τ²-bench Retail79.6%—
τ²-bench Telecom92.3%—
Cybench82%—
DeepResearch Bench54.8%—
OSWorld66.3%—
BALROG43.5%—
GDP.pdf—19.8%
LMArena Search1180—
METR Time Horizons75%—
Vending-Bench 24,967—

Reasoning DeepSeek V4.1 Flash leads

Claude Opus 4.5: 42.6 (#51), DeepSeek V4.1 Flash: 50.2 (#36)

BenchmarkClaude Opus 4.5DeepSeek V4.1 Flash
NYT Connections (extended)52.5%89.6%
LMArena Hard Prompts14761483
Mystery Game Puzzles22%43%
DTBench89.9%89.9%
LMCA44.5%47%
Epoch Capabilities Index150.09154.9
ARC-AGI-237.6%—
SimpleBench62%—
Kagi LLM Benchmark80.2%—
ARC-AGI-180%—
CritPt—14.3%
Chess Puzzles12%—
EnigmaEval11.9%—
EBR-Bench14.3%—
Surface Evolver Bench—46.3%
ForecastBench60.7—

Math DeepSeek V4.1 Flash leads

Claude Opus 4.5: 38.6 (#132), DeepSeek V4.1 Flash: 66.7 (#25)

BenchmarkClaude Opus 4.5DeepSeek V4.1 Flash
FrontierMath (Tiers 1-3)34.4%67.4%
FrontierMath Tier 44.9%26.8%
OTIS Mock AIME 2024-202586.1%98.3%
ProofBench36%54%
LMArena Math14631477
FrontierMath (Feb 2025 set)20.7%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge DeepSeek V4.1 Flash leads

Claude Opus 4.5: 56.5 (#44), DeepSeek V4.1 Flash: 57.9 (#38)

BenchmarkClaude Opus 4.5DeepSeek V4.1 Flash
GPQA Diamond86%89.8%
LMArena Expert14871506
Humanity's Last Exam25.2%—
SimpleQA Verified45.7%—
Vectara Hallucination Rate10.9%—

Multimodal DeepSeek V4.1 Flash leads

Claude Opus 4.5: 31.4 (#107), DeepSeek V4.1 Flash: 39.1 (#61)

BenchmarkClaude Opus 4.5DeepSeek V4.1 Flash
Furniture Assembly28.3%34.2%
LMArena Vision—1277
GeoBench75%—
VPCT40%—
LMArena Document1462—

Multilingual Too close to call

Claude Opus 4.5: 54.3 (#47), DeepSeek V4.1 Flash: 55.0 (#35)

BenchmarkClaude Opus 4.5DeepSeek V4.1 Flash
LMArena Non-English14381448
LMArena Chinese14701497
LMArena French14711452
LMArena German14491484
LMArena Japanese14161412
LMArena Korean14241452
LMArena Russian14471471
LMArena Spanish14581459

Instruction Following Too close to call

Claude Opus 4.5: 77.5 (#19), DeepSeek V4.1 Flash: 77.3 (#26)

BenchmarkClaude Opus 4.5DeepSeek V4.1 Flash
LMArena Instruction Following14781474

Long Context Claude Opus 4.5 leads

Claude Opus 4.5: 46.5 (#22), DeepSeek V4.1 Flash: 45.2 (#47)

BenchmarkClaude Opus 4.5DeepSeek V4.1 Flash
LMArena Longer Query14801475
CL-bench21.1%—

Writing & Preference Claude Opus 4.5 leads

Claude Opus 4.5: 68.1 (#28), DeepSeek V4.1 Flash: 65.4 (#48)

BenchmarkClaude Opus 4.5DeepSeek V4.1 Flash
LMArena Text14511462
LMArena Creative Writing14451435
EQ-Bench Creative Writing16871540
LMArena Multi-Turn14661457

Frequently asked questions

Is Claude Opus 4.5 better than DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash is the stronger model overall, scoring 52.8 to 50.5 on the Noometry Index.

Which is cheaper, Claude Opus 4.5 or DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; Claude Opus 4.5 lists at $5 and $25.

Is Claude Opus 4.5 or DeepSeek V4.1 Flash better for coding?

Claude Opus 4.5 scores higher on coding benchmarks: 54.8 versus 52.9 in the Noometry coding category.

Which has the bigger context window?

DeepSeek V4.1 Flash does, with 1M tokens against 200K.

How many benchmarks do Claude Opus 4.5 and DeepSeek V4.1 Flash share?

31 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and DeepSeek V4.1 Flash has 37.

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