Model comparison

Claude Sonnet 5.5 vs DeepSeek-R1

Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 42.3 on the Noometry Index. DeepSeek-R1 costs 4.4× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.

Last verified October 10, 2026. 18 shared benchmarks.

Claude Sonnet 5.5 Anthropic

61.9

Rank #10 Confirmed

DeepSeek-R1

DeepSeek

42.3

Rank #115 Confirmed

Summary

They share 18 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 9 categories and DeepSeek-R1 in 0 categories; 8 gaps are clear of the uncertainty.
The widest gap is in math, where Claude Sonnet 5.5 leads 87.9 to 43.8.
The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 100% for Claude Sonnet 5.5 and 66.4% for DeepSeek-R1.
DeepSeek-R1 is cheaper at $0.50 / $2.15 per million input/output tokens, against $2 / $10 for Claude Sonnet 5.5.
Claude Sonnet 5.5 accepts more context: 1M tokens versus 164K.

Side by side

Claude Sonnet 5.5 and DeepSeek-R1 specifications
	Claude Sonnet 5.5	DeepSeek-R1
Provider	Anthropic	DeepSeek
Noometry Index	61.9	42.3
Released	2026-09-28	2025-01-20
Weights	Proprietary	Proprietary
Context window	1M	164K
Max output	128K	64K
Input $ / M tokens	$2	$0.50
Output $ / M tokens	$10	$2.15
Results tracked	32	52

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Category by category

Coding Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 67.3 (#6), DeepSeek-R1: 46.3 (#68)

Coding benchmarks
Benchmark	Claude Sonnet 5.5	DeepSeek-R1
SciCode	61%	35.7%
LMArena Coding	1513	1427
ALE-Bench	1,819	804.12
FrontierCode	52.1%	—
Aider Polyglot	—	71.4%
CursorBench	55.5%	—
LMArena WebDev	1774	—
FrontierSWE	61.9%	—
WeirdML	—	41.6%
LiveBench Coding	—	66.7%
AlgoTune	—	1.7

Agentic & Tool Use Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 45.0 (#16), DeepSeek-R1: 30.7 (#75)

Agentic & Tool Use benchmarks
Benchmark	Claude Sonnet 5.5	DeepSeek-R1
APEX-Agents	75.5%	—
DeepResearch Bench	—	35.1%
BALROG	—	34.9%
METR Time Horizons	—	53.8%

Reasoning Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 54.0 (#28), DeepSeek-R1: 18.6 (#278)

Reasoning benchmarks
Benchmark	Claude Sonnet 5.5	DeepSeek-R1
CritPt	31.4%	1.1%
LMArena Hard Prompts	1495	1416
Epoch Capabilities Index	165.03	141.29
ARC-AGI-2	—	1.3%
SimpleBench	—	40.8%
Kagi LLM Benchmark	—	69.4%
NYT Connections (extended)	80.5%	—
ARC-AGI-1	—	21.2%
LiveBench Reasoning	—	83.2%
Mystery Game Puzzles	65%	—
LiveBench Data Analysis	—	69.8%
ForecastBench	—	60
LiveBench	—	71.6%

Math Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 87.9 (#6), DeepSeek-R1: 43.8 (#79)

Math benchmarks
Benchmark	Claude Sonnet 5.5	DeepSeek-R1
OTIS Mock AIME 2024-2025	100%	66.4%
LMArena Math	1510	1400
FrontierMath (Tiers 1-3)	88.8%	—
FrontierMath Tier 4	80.5%	—
ProofBench	100%	—
Omni-MATH	—	42.4%
LiveBench Math	—	80.7%
MATH Level 5	—	96.6%
FrontierMath Erdős	2.9%	—

Knowledge Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 66.0 (#12), DeepSeek-R1: 44.5 (#87)

Knowledge benchmarks
Benchmark	Claude Sonnet 5.5	DeepSeek-R1
GPQA Diamond	95.6%	76.3%
LMArena Expert	1540	1394
SimpleQA Verified	46.5%	—
MMLU-Pro	—	79.3%
Confabulations	—	12.7%
Vectara Hallucination Rate	—	11.3%
GPQA (HELM)	—	66.6%

Multimodal Not comparable

Claude Sonnet 5.5: 51.5 (#6), DeepSeek-R1: —

Multimodal benchmarks
Benchmark	Claude Sonnet 5.5	DeepSeek-R1
LMArena Vision	1289	—
Furniture Assembly	75%	—

Multilingual Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 55.3 (#30), DeepSeek-R1: 52.4 (#85)

Multilingual benchmarks
Benchmark	Claude Sonnet 5.5	DeepSeek-R1
LMArena Non-English	1452	1412
LMArena Chinese	1522	1442
LMArena Russian	1451	1423
LMArena French	—	1417
LMArena German	—	1404
LMArena Japanese	—	1391
LMArena Korean	—	1360
LMArena Spanish	—	1411

Instruction Following Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 78.3 (#11), DeepSeek-R1: 72.0 (#143)

Instruction Following benchmarks
Benchmark	Claude Sonnet 5.5	DeepSeek-R1
LMArena Instruction Following	1495	1382
LiveBench Instruction Following	—	80.5%
IFEval	—	78.4%

Long Context Too close to call

Claude Sonnet 5.5: 45.9 (#28), DeepSeek-R1: 45.4 (#36)

Long Context benchmarks
Benchmark	Claude Sonnet 5.5	DeepSeek-R1
LMArena Longer Query	1498	1391
Fiction.LiveBench	—	75%

Writing & Preference Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 66.0 (#40), DeepSeek-R1: 61.4 (#88)

Writing & Preference benchmarks
Benchmark	Claude Sonnet 5.5	DeepSeek-R1
LMArena Text	1471	1428
LMArena Creative Writing	1465	1405
LMArena Multi-Turn	1474	1405
Short-Story Creative Writing	—	83%
EQ-Bench Creative Writing	—	1500
WildBench	—	82.8%
LiveBench Language	—	48.5%

Frequently asked questions

Is Claude Sonnet 5.5 better than DeepSeek-R1?

Which is cheaper, Claude Sonnet 5.5 or DeepSeek-R1?

DeepSeek-R1 is cheaper. It lists at $0.50 per million input tokens and $2.15 per million output tokens; Claude Sonnet 5.5 lists at $2 and $10.

Is Claude Sonnet 5.5 or DeepSeek-R1 better for coding?

Claude Sonnet 5.5 scores higher on coding benchmarks: 67.3 versus 46.3 in the Noometry coding category.

Which has the bigger context window?

Claude Sonnet 5.5 does, with 1M tokens against 164K.

How many benchmarks do Claude Sonnet 5.5 and DeepSeek-R1 share?

18 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and DeepSeek-R1 has 52.