Model comparison

Claude Sonnet 5 vs DeepSeek V4 Flash

Claude Sonnet 5 is the stronger model overall, scoring 54.6 to 53.6 on the Noometry Index. DeepSeek V4 Flash costs 15× less per token, which makes it the better buy when Claude Sonnet 5's lead doesn't matter for your workload.

Last verified . 37 shared benchmarks.

Claude Sonnet 5 Anthropic

54.6

Rank #29 Confirmed

DeepSeek V4 Flash DeepSeek

53.6

Rank #35 Confirmed

Summary

  • They share 37 benchmarks with published results for both. Claude Sonnet 5 scores higher in 7 categories and DeepSeek V4 Flash in 1 category; 5 gaps are clear of the uncertainty.
  • The widest gap is in coding, where Claude Sonnet 5 leads 55.5 to 47.9.
  • The biggest single-benchmark swing is FrontierCode: 42.7% for Claude Sonnet 5 and 18.8% for DeepSeek V4 Flash.
  • DeepSeek V4 Flash is cheaper at $0.15 / $0.60 per million input/output tokens, against $2 / $10 for Claude Sonnet 5.
  • DeepSeek V4 Flash has downloadable open weights; the other is API-only.

Side by side

Claude Sonnet 5 and DeepSeek V4 Flash specifications
Claude Sonnet 5DeepSeek V4 Flash
ProviderAnthropicDeepSeek
Noometry Index54.653.6
Released2026-06-292026-04-24
WeightsProprietaryOpen
Context window1M1M
Max output128K393K
Input $ / M tokens$2$0.15
Output $ / M tokens$10$0.60
Results tracked5141

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Category by category

Coding Claude Sonnet 5 leads

Claude Sonnet 5: 55.5 (#26), DeepSeek V4 Flash: 47.9 (#59)

Coding benchmarks
BenchmarkClaude Sonnet 5DeepSeek V4 Flash
FrontierCode42.7%18.8%
LMArena WebDev15411582
SciCode54.3%49.9%
WeirdML68.8%63%
LMArena Coding14831457
ALE-Bench1,4631,306
DeepSWE53.8%—
CursorBench34.1%—
GSO37.3%—

Agentic & Tool Use Not comparable

Claude Sonnet 5: 42.8 (#18), DeepSeek V4 Flash: —

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 5DeepSeek V4 Flash
APEX-Agents54.5%—
GBAEval65.3%—
LMArena Search1194—
Vending-Bench 26,378—

Reasoning DeepSeek V4 Flash leads

Claude Sonnet 5: 49.1 (#39), DeepSeek V4 Flash: 53.7 (#30)

Reasoning benchmarks
BenchmarkClaude Sonnet 5DeepSeek V4 Flash
SimpleBench60.6%61.1%
NYT Connections (extended)75.1%89.6%
CritPt16.9%16.6%
Chess Puzzles35%33%
LMArena Hard Prompts14611444
Mystery Game Puzzles35%34%
DTBench92.5%90.9%
LMCA50%41.7%
Epoch Capabilities Index156.21154.49
ARC-AGI-2—61.4%
Kagi LLM Benchmark—52.2%
ARC-AGI-1—89%
Surface Evolver Bench60%—
Bench to the Future 30.14—
ForecastBench61.1—

Math Claude Sonnet 5 leads

Claude Sonnet 5: 66.2 (#27), DeepSeek V4 Flash: 60.3 (#37)

Math benchmarks
BenchmarkClaude Sonnet 5DeepSeek V4 Flash
FrontierMath (Tiers 1-3)65.6%57.5%
FrontierMath Tier 429.3%24.4%
OTIS Mock AIME 2024-202594.7%94.4%
ProofBench77%56%
LMArena Math14671427
MathArena Final-Answer Competitions—76.5%

Knowledge Too close to call

Claude Sonnet 5: 55.6 (#47), DeepSeek V4 Flash: 55.4 (#48)

Knowledge benchmarks
BenchmarkClaude Sonnet 5DeepSeek V4 Flash
GPQA Diamond90.5%91%
SimpleQA Verified33.7%33.6%
LMArena Expert14901441

Multimodal Not comparable

Claude Sonnet 5: 42.4 (#31), DeepSeek V4 Flash: —

Multimodal benchmarks
BenchmarkClaude Sonnet 5DeepSeek V4 Flash
LMArena Vision1274—
Blueprint-Bench 224.9%—
LMArena Document1466—

Multilingual Too close to call

Claude Sonnet 5: 53.8 (#55), DeepSeek V4 Flash: 53.0 (#72)

Multilingual benchmarks
BenchmarkClaude Sonnet 5DeepSeek V4 Flash
LMArena Non-English14311420
LMArena Chinese14771468
LMArena French14601439
LMArena German14401418
LMArena Japanese14221406
LMArena Korean14111384
LMArena Russian14511428
LMArena Spanish14371436

Instruction Following Claude Sonnet 5 leads

Claude Sonnet 5: 76.3 (#41), DeepSeek V4 Flash: 74.9 (#81)

Instruction Following benchmarks
BenchmarkClaude Sonnet 5DeepSeek V4 Flash
LMArena Instruction Following14521421

Long Context Too close to call

Claude Sonnet 5: 44.8 (#55), DeepSeek V4 Flash: 43.8 (#85)

Long Context benchmarks
BenchmarkClaude Sonnet 5DeepSeek V4 Flash
LMArena Longer Query14631434

Writing & Preference Claude Sonnet 5 leads

Claude Sonnet 5: 69.2 (#25), DeepSeek V4 Flash: 63.8 (#61)

Writing & Preference benchmarks
BenchmarkClaude Sonnet 5DeepSeek V4 Flash
LMArena Text14421432
LMArena Creative Writing14161403
EQ-Bench Creative Writing17941559
LMArena Multi-Turn14541449
EQ-Bench 41236—

Frequently asked questions

Is Claude Sonnet 5 better than DeepSeek V4 Flash?

Claude Sonnet 5 is the stronger model overall, scoring 54.6 to 53.6 on the Noometry Index. DeepSeek V4 Flash costs 15× less per token, which makes it the better buy when Claude Sonnet 5's lead doesn't matter for your workload.

Which is cheaper, Claude Sonnet 5 or DeepSeek V4 Flash?

DeepSeek V4 Flash is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; Claude Sonnet 5 lists at $2 and $10.

Is Claude Sonnet 5 or DeepSeek V4 Flash better for coding?

Claude Sonnet 5 scores higher on coding benchmarks: 55.5 versus 47.9 in the Noometry coding category.

Which has the bigger context window?

Both accept 1M tokens.

How many benchmarks do Claude Sonnet 5 and DeepSeek V4 Flash share?

37 benchmarks have published results for both models. Claude Sonnet 5 has 51 scored results on Noometry and DeepSeek V4 Flash has 41.

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