Model comparison

Claude Sonnet 5.5 vs Kimi K2.7 Code

Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 43.3 on the Noometry Index. Kimi K2.7 Code costs 2.3× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.

Last verified . 12 shared benchmarks.

Claude Sonnet 5.5 Anthropic

61.9

Rank #10 Confirmed

Kimi K2.7 Code Moonshot AI

43.3

Rank #94 Confirmed

Summary

  • They share 12 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 5 categories and Kimi K2.7 Code in 0 categories; 5 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Sonnet 5.5 leads 87.9 to 52.9.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 80.5% for Claude Sonnet 5.5 and 12.2% for Kimi K2.7 Code.
  • Kimi K2.7 Code is cheaper at $0.95 / $4 per million input/output tokens, against $2 / $10 for Claude Sonnet 5.5.
  • Claude Sonnet 5.5 accepts more context: 1M tokens versus 262K.
  • Kimi K2.7 Code has downloadable open weights; the other is API-only.

Side by side

Claude Sonnet 5.5 and Kimi K2.7 Code specifications
Claude Sonnet 5.5Kimi K2.7 Code
ProviderAnthropicMoonshot AI
Noometry Index61.943.3
Released2026-09-282026-06-12
WeightsProprietaryOpen
Context window1M262K
Max output128K262K
Input $ / M tokens$2$0.95
Output $ / M tokens$10$4
Results tracked3219

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Category by category

Coding Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 67.3 (#6), Kimi K2.7 Code: 42.9 (#95)

Coding benchmarks
BenchmarkClaude Sonnet 5.5Kimi K2.7 Code
FrontierCode52.1%30.1%
LMArena WebDev17741473
SciCode61%47.5%
ALE-Bench1,819886.23
DeepSWE—30.5%
CursorBench55.5%—
FrontierSWE61.9%—
WeirdML—54.1%
LMArena Coding1513—

Agentic & Tool Use Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 45.0 (#16), Kimi K2.7 Code: 24.0 (#122)

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 5.5Kimi K2.7 Code
APEX-Agents75.5%37.6%
GBAEval—0.9%
Vending-Bench 2—5,083

Reasoning Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 54.0 (#28), Kimi K2.7 Code: 39.0 (#61)

Reasoning benchmarks
BenchmarkClaude Sonnet 5.5Kimi K2.7 Code
CritPt31.4%10%
Epoch Capabilities Index165.03149.97
SimpleBench—57.9%
NYT Connections (extended)80.5%—
Chess Puzzles—21%
LMArena Hard Prompts1495—
Mystery Game Puzzles65%—
Surface Evolver Bench—48.8%

Math Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 87.9 (#6), Kimi K2.7 Code: 52.9 (#48)

Math benchmarks
BenchmarkClaude Sonnet 5.5Kimi K2.7 Code
FrontierMath (Tiers 1-3)88.8%54%
FrontierMath Tier 480.5%12.2%
OTIS Mock AIME 2024-2025100%95.6%
ProofBench100%—
LMArena Math1510—
FrontierMath Erdős2.9%—

Knowledge Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 66.0 (#12), Kimi K2.7 Code: 53.5 (#57)

Knowledge benchmarks
BenchmarkClaude Sonnet 5.5Kimi K2.7 Code
GPQA Diamond95.6%87.9%
SimpleQA Verified46.5%36.5%
LMArena Expert1540—

Multimodal Not comparable

Claude Sonnet 5.5: 51.5 (#6), Kimi K2.7 Code: —

Multimodal benchmarks
BenchmarkClaude Sonnet 5.5Kimi K2.7 Code
LMArena Vision1289—
Furniture Assembly75%—

Multilingual Not comparable

Claude Sonnet 5.5: 55.3 (#30), Kimi K2.7 Code: —

Multilingual benchmarks
BenchmarkClaude Sonnet 5.5Kimi K2.7 Code
LMArena Non-English1452—
LMArena Chinese1522—
LMArena Russian1451—

Instruction Following Not comparable

Claude Sonnet 5.5: 78.3 (#11), Kimi K2.7 Code: —

Instruction Following benchmarks
BenchmarkClaude Sonnet 5.5Kimi K2.7 Code
LMArena Instruction Following1495—

Long Context Not comparable

Claude Sonnet 5.5: 45.9 (#28), Kimi K2.7 Code: —

Long Context benchmarks
BenchmarkClaude Sonnet 5.5Kimi K2.7 Code
LMArena Longer Query1498—

Writing & Preference Not comparable

Claude Sonnet 5.5: 66.0 (#40), Kimi K2.7 Code: —

Writing & Preference benchmarks
BenchmarkClaude Sonnet 5.5Kimi K2.7 Code
LMArena Text1471—
LMArena Creative Writing1465—
LMArena Multi-Turn1474—

Frequently asked questions

Is Claude Sonnet 5.5 better than Kimi K2.7 Code?

Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 43.3 on the Noometry Index. Kimi K2.7 Code costs 2.3× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.

Which is cheaper, Claude Sonnet 5.5 or Kimi K2.7 Code?

Kimi K2.7 Code is cheaper. It lists at $0.95 per million input tokens and $4 per million output tokens; Claude Sonnet 5.5 lists at $2 and $10.

Is Claude Sonnet 5.5 or Kimi K2.7 Code better for coding?

Claude Sonnet 5.5 scores higher on coding benchmarks: 67.3 versus 42.9 in the Noometry coding category.

Which has the bigger context window?

Claude Sonnet 5.5 does, with 1M tokens against 262K.

How many benchmarks do Claude Sonnet 5.5 and Kimi K2.7 Code share?

12 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and Kimi K2.7 Code has 19.

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