Model comparison

Claude Opus 4 vs Claude Sonnet 5.5

Claude Sonnet 5.5 is the stronger model overall, scoring 60.5 to 42.9 on the Noometry Index.

Last verified . 3 shared benchmarks.

Claude Opus 4 Anthropic

42.9

Rank #93 Confirmed

Claude Sonnet 5.5 Anthropic

60.5

Rank #10 Confirmed

Summary

  • They share 3 benchmarks with published results for both. Claude Opus 4 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 40.2.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 64.4% for Claude Opus 4 and 100% for Claude Sonnet 5.5.
  • Claude Sonnet 5.5 is cheaper at $2 / $10 per million input/output tokens, against $15 / $75 for Claude Opus 4.
  • Claude Sonnet 5.5 accepts more context: 1M tokens versus 200K.

Side by side

Claude Opus 4 and Claude Sonnet 5.5 specifications
Claude Opus 4Claude Sonnet 5.5
ProviderAnthropicAnthropic
Noometry Index42.960.5
Released2025-05-222026-09-28
WeightsProprietaryProprietary
Context window200K1M
Max output32K128K
Input $ / M tokens$15$2
Output $ / M tokens$75$10
Results tracked5616

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding Claude Sonnet 5.5 leads

Claude Opus 4: 47.8 (#55), Claude Sonnet 5.5: 65.5 (#6)

Coding benchmarks
BenchmarkClaude Opus 4Claude Sonnet 5.5
SWE-bench Verified70.7%—
FrontierCode—52.1%
SWE-bench Verified (bash only)67.6%—
Aider Polyglot72%—
CursorBench—55.5%
LMArena WebDev—1699
FrontierSWE—61.9%
SciCode—61%
GSO6.9%—
WeirdML43.7%—
LMArena Coding1442—
ALE-Bench—1,819
AlgoTune1.33—

Agentic & Tool Use Claude Sonnet 5.5 leads

Claude Opus 4: 34.5 (#39), Claude Sonnet 5.5: 44.9 (#14)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4Claude Sonnet 5.5
APEX-Agents—75.5%
Cybench38%—
DeepResearch Bench46.8%—
LMArena Search1127—
METR Time Horizons63.9%—

Reasoning Claude Sonnet 5.5 leads

Claude Opus 4: 27.4 (#104), Claude Sonnet 5.5: 52.4 (#29)

Reasoning benchmarks
BenchmarkClaude Opus 4Claude Sonnet 5.5
CritPt0.3%31.4%
ARC-AGI-28.6%—
SimpleBench58.8%—
Kagi LLM Benchmark74.3%—
ARC-AGI-135.7%—
EnigmaEval5.6%—
LMArena Hard Prompts1399—
Mystery Game Puzzles—65%
DTBench81.6%—
LMCA37.4%—
Epoch Capabilities Index142.67—
ForecastBench61.1—

Math Claude Sonnet 5.5 leads

Claude Opus 4: 40.2 (#80), Claude Sonnet 5.5: 88.7 (#4)

Math benchmarks
BenchmarkClaude Opus 4Claude Sonnet 5.5
OTIS Mock AIME 2024-202564.4%100%
FrontierMath (Tiers 1-3)—88.8%
FrontierMath Tier 4—80.5%
ProofBench—100%
Omni-MATH61.6%—
LMArena Math1391—
MATH Level 585%—
FrontierMath (Feb 2025 set)4.5%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge Claude Sonnet 5.5 leads

Claude Opus 4: 43.9 (#82), Claude Sonnet 5.5: 66.0 (#11)

Knowledge benchmarks
BenchmarkClaude Opus 4Claude Sonnet 5.5
GPQA Diamond76.3%95.6%
Humanity's Last Exam10.7%—
SimpleQA Verified—46.5%
MMLU-Pro87.5%—
Confabulations15.9%—
Vectara Hallucination Rate12%—
GPQA (HELM)70.8%—
LMArena Expert1384—

Multimodal Claude Sonnet 5.5 leads

Claude Opus 4: 30.9 (#101), Claude Sonnet 5.5: 53.2 (#5)

Multimodal benchmarks
BenchmarkClaude Opus 4Claude Sonnet 5.5
LMArena Vision1192—
GeoBench49%—
VPCT38%—
Furniture Assembly—75%

Multilingual Not comparable

Claude Opus 4: 49.0 (#133), Claude Sonnet 5.5: —

Multilingual benchmarks
BenchmarkClaude Opus 4Claude Sonnet 5.5
LMArena Non-English1362—
LMArena Chinese1386—
LMArena French1370—
LMArena German1391—
LMArena Japanese1332—
LMArena Korean1318—
LMArena Russian1392—
LMArena Spanish1388—

Instruction Following Not comparable

Claude Opus 4: 77.3 (#26), Claude Sonnet 5.5: —

Instruction Following benchmarks
BenchmarkClaude Opus 4Claude Sonnet 5.5
IFEval91.8%—
LMArena Instruction Following1406—

Long Context Not comparable

Claude Opus 4: 39.5 (#167), Claude Sonnet 5.5: —

Long Context benchmarks
BenchmarkClaude Opus 4Claude Sonnet 5.5
Fiction.LiveBench61.1%—
LMArena Longer Query1422—

Writing & Preference Not comparable

Claude Opus 4: 61.4 (#85), Claude Sonnet 5.5: —

Writing & Preference benchmarks
BenchmarkClaude Opus 4Claude Sonnet 5.5
LMArena Text1377—
LMArena Creative Writing1386—
Short-Story Creative Writing83.6%—
EQ-Bench Creative Writing1580—
WildBench85.2%—
LMArena Multi-Turn1396—

Frequently asked questions

Is Claude Opus 4 better than Claude Sonnet 5.5?

Claude Sonnet 5.5 is the stronger model overall, scoring 60.5 to 42.9 on the Noometry Index.

Which is cheaper, Claude Opus 4 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 Opus 4 lists at $15 and $75.

Is Claude Opus 4 or Claude Sonnet 5.5 better for coding?

Claude Sonnet 5.5 scores higher on coding benchmarks: 65.5 versus 47.8 in the Noometry coding category.

Which has the bigger context window?

Claude Sonnet 5.5 does, with 1M tokens against 200K.

How many benchmarks do Claude Opus 4 and Claude Sonnet 5.5 share?

3 benchmarks have published results for both models. Claude Opus 4 has 56 scored results on Noometry and Claude Sonnet 5.5 has 16.

Related comparisons

Go deeper