Model comparison

Claude Sonnet 4.6 vs Claude Sonnet 5.5

Claude Sonnet 5.5 is the stronger model overall, scoring 60.5 to 50.1 on the Noometry Index.

Last verified . 11 shared benchmarks.

Claude Sonnet 4.6 Anthropic

50.1

Rank #42 Confirmed

Claude Sonnet 5.5 Anthropic

60.5

Rank #10 Confirmed

Summary

  • They share 11 benchmarks with published results for both. Claude Sonnet 4.6 scores higher in 0 categories and Claude Sonnet 5.5 in 6 categories; 6 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Sonnet 5.5 leads 88.7 to 51.9.
  • The biggest single-benchmark swing is ProofBench: 45% for Claude Sonnet 4.6 and 100% for Claude Sonnet 5.5.
  • Claude Sonnet 5.5 is cheaper at $2 / $10 per million input/output tokens, against $3 / $15 for Claude Sonnet 4.6.

Side by side

Claude Sonnet 4.6 and Claude Sonnet 5.5 specifications
Claude Sonnet 4.6Claude Sonnet 5.5
ProviderAnthropicAnthropic
Noometry Index50.160.5
Released2026-02-172026-09-28
WeightsProprietaryProprietary
Context window1M1M
Max output128K128K
Input $ / M tokens$3$2
Output $ / M tokens$15$10
Results tracked5716

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Category by category

Coding Claude Sonnet 5.5 leads

Claude Sonnet 4.6: 46.0 (#62), Claude Sonnet 5.5: 65.5 (#6)

Coding benchmarks
BenchmarkClaude Sonnet 4.6Claude Sonnet 5.5
FrontierCode24.3%52.1%
LMArena WebDev15211699
SciCode46.8%61%
ALE-Bench1,3271,819
SWE-bench Verified75.2%—
DeepSWE29.9%—
CursorBench—55.5%
FrontierSWE—61.9%
WeirdML66.1%—
LMArena Coding1504—

Agentic & Tool Use Claude Sonnet 5.5 leads

Claude Sonnet 4.6: 39.1 (#26), Claude Sonnet 5.5: 44.9 (#14)

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 4.6Claude Sonnet 5.5
APEX-Agents43%75.5%
Terminal-Bench53.4%—
OSWorld 2.09.3%—
DeepResearch Bench54.9%—
OSWorld72.1%—
ExploitBench23.6%—
GBAEval48.8%—
GDP.pdf18%—
LMArena Search1221—
Vending-Bench 27,204—

Reasoning Claude Sonnet 5.5 leads

Claude Sonnet 4.6: 46.1 (#40), Claude Sonnet 5.5: 52.4 (#29)

Reasoning benchmarks
BenchmarkClaude Sonnet 4.6Claude Sonnet 5.5
CritPt3.1%31.4%
Mystery Game Puzzles16%65%
ARC-AGI-260.4%—
NYT Connections (extended)80.9%—
ARC-AGI-186.5%—
Chess Puzzles13%—
Thematic Generalization76.3%—
LMArena Hard Prompts1485—
DTBench89.9%—
LMCA46.5%—
Epoch Capabilities Index152.25—
ForecastBench62—

Math Claude Sonnet 5.5 leads

Claude Sonnet 4.6: 51.9 (#41), Claude Sonnet 5.5: 88.7 (#4)

Math benchmarks
BenchmarkClaude Sonnet 4.6Claude Sonnet 5.5
OTIS Mock AIME 2024-202585.8%100%
ProofBench45%100%
FrontierMath (Tiers 1-3)—88.8%
FrontierMath Tier 4—80.5%
LMArena Math1463—
FrontierMath (Feb 2025 set)32.4%—
FrontierMath Tier 4 (v1)8.3%—

Knowledge Claude Sonnet 5.5 leads

Claude Sonnet 4.6: 51.6 (#60), Claude Sonnet 5.5: 66.0 (#11)

Knowledge benchmarks
BenchmarkClaude Sonnet 4.6Claude Sonnet 5.5
GPQA Diamond87.4%95.6%
SimpleQA Verified35.5%46.5%
Vectara Hallucination Rate10.6%—
LMArena Expert1500—

Multimodal Claude Sonnet 5.5 leads

Claude Sonnet 4.6: 38.0 (#61), Claude Sonnet 5.5: 53.2 (#5)

Multimodal benchmarks
BenchmarkClaude Sonnet 4.6Claude Sonnet 5.5
LMArena Vision1283—
Blueprint-Bench 26.7%—
Furniture Assembly—75%
LMArena Document1482—

Multilingual Not comparable

Claude Sonnet 4.6: 54.6 (#39), Claude Sonnet 5.5: —

Multilingual benchmarks
BenchmarkClaude Sonnet 4.6Claude Sonnet 5.5
LMArena Non-English1440—
LMArena Chinese1491—
LMArena French1465—
LMArena German1428—
LMArena Japanese1419—
LMArena Korean1411—
LMArena Russian1440—
LMArena Spanish1465—

Instruction Following Not comparable

Claude Sonnet 4.6: 77.6 (#23), Claude Sonnet 5.5: —

Instruction Following benchmarks
BenchmarkClaude Sonnet 4.6Claude Sonnet 5.5
LMArena Instruction Following1476—

Long Context Not comparable

Claude Sonnet 4.6: 45.3 (#40), Claude Sonnet 5.5: —

Long Context benchmarks
BenchmarkClaude Sonnet 4.6Claude Sonnet 5.5
LMArena Longer Query1479—

Writing & Preference Not comparable

Claude Sonnet 4.6: 70.4 (#22), Claude Sonnet 5.5: —

Writing & Preference benchmarks
BenchmarkClaude Sonnet 4.6Claude Sonnet 5.5
LMArena Text1458—
LMArena Creative Writing1435—
EQ-Bench Creative Writing1810—
EQ-Bench 41207—
LMArena Multi-Turn1464—

Frequently asked questions

Is Claude Sonnet 4.6 better than Claude Sonnet 5.5?

Claude Sonnet 5.5 is the stronger model overall, scoring 60.5 to 50.1 on the Noometry Index.

Which is cheaper, Claude Sonnet 4.6 or Claude Sonnet 5.5?

Claude Sonnet 5.5 is cheaper. It lists at $2 per million input tokens and $10 per million output tokens; Claude Sonnet 4.6 lists at $3 and $15.

Is Claude Sonnet 4.6 or Claude Sonnet 5.5 better for coding?

Claude Sonnet 5.5 scores higher on coding benchmarks: 65.5 versus 46.0 in the Noometry coding category.

Which has the bigger context window?

Both accept 1M tokens.

How many benchmarks do Claude Sonnet 4.6 and Claude Sonnet 5.5 share?

11 benchmarks have published results for both models. Claude Sonnet 4.6 has 57 scored results on Noometry and Claude Sonnet 5.5 has 16.

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