Model comparison

Claude Sonnet 4.6 vs DeepSeek-V3.1-Terminus

Claude Sonnet 4.6 is the stronger model overall, scoring 50.3 to 43.1 on the Noometry Index. DeepSeek-V3.1-Terminus costs 13× less per token, which makes it the better buy when Claude Sonnet 4.6's lead doesn't matter for your workload.

Last verified . 15 shared benchmarks.

Claude Sonnet 4.6 Anthropic

50.3

Rank #50 Confirmed

DeepSeek-V3.1-Terminus DeepSeek

43.1

Rank #97 Confirmed

Summary

  • They share 15 benchmarks with published results for both. Claude Sonnet 4.6 scores higher in 7 categories and DeepSeek-V3.1-Terminus in 0 categories; 7 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Sonnet 4.6 leads 46.1 to 26.4.
  • The biggest single-benchmark swing is LMCA: 46.5% for Claude Sonnet 4.6 and 28.6% for DeepSeek-V3.1-Terminus.
  • DeepSeek-V3.1-Terminus is cheaper at $0.27 / $1 per million input/output tokens, against $3 / $15 for Claude Sonnet 4.6.
  • Claude Sonnet 4.6 accepts more context: 1M tokens versus 164K.
  • DeepSeek-V3.1-Terminus has downloadable open weights; the other is API-only.

Side by side

Claude Sonnet 4.6 and DeepSeek-V3.1-Terminus specifications
Claude Sonnet 4.6DeepSeek-V3.1-Terminus
ProviderAnthropicDeepSeek
Noometry Index50.343.1
Released2026-02-172025-09-22
WeightsProprietaryOpen
Context window1M164K
Max output128K147K
Input $ / M tokens$3$0.27
Output $ / M tokens$15$1
Results tracked5716

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Category by category

Coding Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 46.3 (#67), DeepSeek-V3.1-Terminus: 42.0 (#113)

Coding benchmarks
BenchmarkClaude Sonnet 4.6DeepSeek-V3.1-Terminus
SciCode46.8%40.6%
LMArena Coding15041426
ALE-Bench1,327745.17
SWE-bench Verified75.2%—
DeepSWE29.9%—
FrontierCode24.3%—
LMArena WebDev1522—
WeirdML66.1%—

Agentic & Tool Use Not comparable

Claude Sonnet 4.6: 39.1 (#28), DeepSeek-V3.1-Terminus: —

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 4.6DeepSeek-V3.1-Terminus
Terminal-Bench53.4%—
APEX-Agents43%—
OSWorld 2.09.3%—
DeepResearch Bench54.9%—
OSWorld72.1%—
ExploitBench23.6%—
GBAEval48.8%—
GDP.pdf18%—
LMArena Search1221—
Vending-Bench 27,204—

Reasoning Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 46.1 (#45), DeepSeek-V3.1-Terminus: 26.4 (#133)

Reasoning benchmarks
BenchmarkClaude Sonnet 4.6DeepSeek-V3.1-Terminus
CritPt3.1%1.7%
LMArena Hard Prompts14841426
DTBench89.9%81.3%
LMCA46.5%28.6%
ARC-AGI-260.4%—
Kagi LLM Benchmark—57.4%
NYT Connections (extended)80.9%—
ARC-AGI-186.5%—
Chess Puzzles13%—
Thematic Generalization76.3%—
Mystery Game Puzzles16%—
Epoch Capabilities Index152.24—
ForecastBench62—

Math Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 52.9 (#49), DeepSeek-V3.1-Terminus: 38.5 (#137)

Math benchmarks
BenchmarkClaude Sonnet 4.6DeepSeek-V3.1-Terminus
LMArena Math14621402
OTIS Mock AIME 2024-202585.8%—
ProofBench45%—
FrontierMath (Feb 2025 set)32.4%—
FrontierMath Tier 4 (v1)8.3%—

Knowledge Not comparable

Claude Sonnet 4.6: 51.7 (#65), DeepSeek-V3.1-Terminus: —

Knowledge benchmarks
BenchmarkClaude Sonnet 4.6DeepSeek-V3.1-Terminus
GPQA Diamond87.4%—
SimpleQA Verified35.5%—
Vectara Hallucination Rate10.6%—
LMArena Expert1500—

Multimodal Not comparable

Claude Sonnet 4.6: 38.0 (#68), DeepSeek-V3.1-Terminus: —

Multimodal benchmarks
BenchmarkClaude Sonnet 4.6DeepSeek-V3.1-Terminus
LMArena Vision1283—
Blueprint-Bench 26.7%—
LMArena Document1482—

Multilingual Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 54.4 (#41), DeepSeek-V3.1-Terminus: 52.1 (#92)

Multilingual benchmarks
BenchmarkClaude Sonnet 4.6DeepSeek-V3.1-Terminus
LMArena Non-English14401407
LMArena Russian14401436
LMArena Chinese1491—
LMArena French1465—
LMArena German1428—
LMArena Japanese1420—
LMArena Korean1411—
LMArena Spanish1464—

Instruction Following Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 77.4 (#25), DeepSeek-V3.1-Terminus: 74.0 (#106)

Instruction Following benchmarks
BenchmarkClaude Sonnet 4.6DeepSeek-V3.1-Terminus
LMArena Instruction Following14751404

Long Context Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 45.3 (#44), DeepSeek-V3.1-Terminus: 43.4 (#97)

Long Context benchmarks
BenchmarkClaude Sonnet 4.6DeepSeek-V3.1-Terminus
LMArena Longer Query14791421

Writing & Preference Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 70.2 (#22), DeepSeek-V3.1-Terminus: 61.0 (#92)

Writing & Preference benchmarks
BenchmarkClaude Sonnet 4.6DeepSeek-V3.1-Terminus
LMArena Text14581419
LMArena Creative Writing14351403
LMArena Multi-Turn14641411
EQ-Bench Creative Writing1810—
EQ-Bench 41207—

Frequently asked questions

Is Claude Sonnet 4.6 better than DeepSeek-V3.1-Terminus?

Claude Sonnet 4.6 is the stronger model overall, scoring 50.3 to 43.1 on the Noometry Index. DeepSeek-V3.1-Terminus costs 13× less per token, which makes it the better buy when Claude Sonnet 4.6's lead doesn't matter for your workload.

Which is cheaper, Claude Sonnet 4.6 or DeepSeek-V3.1-Terminus?

DeepSeek-V3.1-Terminus is cheaper. It lists at $0.27 per million input tokens and $1 per million output tokens; Claude Sonnet 4.6 lists at $3 and $15.

Is Claude Sonnet 4.6 or DeepSeek-V3.1-Terminus better for coding?

Claude Sonnet 4.6 scores higher on coding benchmarks: 46.3 versus 42.0 in the Noometry coding category.

Which has the bigger context window?

Claude Sonnet 4.6 does, with 1M tokens against 164K.

How many benchmarks do Claude Sonnet 4.6 and DeepSeek-V3.1-Terminus share?

15 benchmarks have published results for both models. Claude Sonnet 4.6 has 57 scored results on Noometry and DeepSeek-V3.1-Terminus has 16.

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