Model comparison

Claude Opus 5 vs Kimi K2.5

Claude Opus 5 is the stronger model overall, scoring 67.8 to 48.1 on the Noometry Index. Kimi K2.5 costs 11× less per token, which makes it the better buy when Claude Opus 5's lead doesn't matter for your workload.

Last verified . 35 shared benchmarks.

Claude Opus 5 Anthropic

67.8

Rank #4 Confirmed

Kimi K2.5 Moonshot AI

48.1

Rank #57 Confirmed

Summary

  • They share 35 benchmarks with published results for both. Claude Opus 5 scores higher in 9 categories and Kimi K2.5 in 1 category; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Opus 5 leads 77.2 to 31.2.
  • The biggest single-benchmark swing is ARC-AGI-2: 90.4% for Claude Opus 5 and 11.8% for Kimi K2.5.
  • Kimi K2.5 is cheaper at $0.45 / $2.25 per million input/output tokens, against $5 / $25 for Claude Opus 5.
  • Claude Opus 5 accepts more context: 1M tokens versus 262K.
  • Kimi K2.5 has downloadable open weights; the other is API-only.

Side by side

Claude Opus 5 and Kimi K2.5 specifications
Claude Opus 5Kimi K2.5
ProviderAnthropicMoonshot AI
Noometry Index67.848.1
Released2026-07-242026-01-27
WeightsProprietaryOpen
Context window1M262K
Max output128K262K
Input $ / M tokens$5$0.45
Output $ / M tokens$25$2.25
Results tracked5751

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Category by category

Coding Claude Opus 5 leads

Claude Opus 5: 67.5 (#5), Kimi K2.5: 48.8 (#53)

Coding benchmarks
BenchmarkClaude Opus 5Kimi K2.5
LMArena WebDev16911437
SciCode56.4%49%
WeirdML91.8%45.6%
LMArena Coding15341474
ALE-Bench2,165821.65
SWE-bench Verified—73.8%
DeepSWE73.6%—
FrontierCode53.4%—
SWE-bench Verified (bash only)—70.8%
CursorBench46.6%—
SWE-bench Multilingual—67.3%
FrontierSWE52%—

Agentic & Tool Use Claude Opus 5 leads

Claude Opus 5: 55.6 (#1), Kimi K2.5: 34.2 (#48)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 5Kimi K2.5
Vending-Bench 211,1821,198
Terminal-Bench—43.2%
APEX-Agents65.8%—
OSWorld 2.031.4%—
τ²-bench Banking48.7%—
OSWorld—63.3%
PostTrainBench35%—
BALROG63.4%—
GBAEval79.6%—
GDP.pdf24%—

Reasoning Claude Opus 5 leads

Claude Opus 5: 77.2 (#4), Kimi K2.5: 31.2 (#80)

Reasoning benchmarks
BenchmarkClaude Opus 5Kimi K2.5
ARC-AGI-290.4%11.8%
SimpleBench80.6%46.8%
NYT Connections (extended)94.3%69.9%
ARC-AGI-197.5%65.3%
CritPt29.1%3.1%
Chess Puzzles42%12%
LMArena Hard Prompts15261453
Epoch Capabilities Index162.78148.03
Kagi LLM Benchmark—78.5%
EnigmaEval—3.4%
Thematic Generalization—69.4%
EBR-Bench45.7%—
Mystery Game Puzzles59%—
DTBench97.9%—
LMCA64.5%—
Bench to the Future 30.12—

Math Claude Opus 5 leads

Claude Opus 5: 86.2 (#8), Kimi K2.5: 51.8 (#53)

Knowledge Claude Opus 5 leads

Claude Opus 5: 66.8 (#9), Kimi K2.5: 53.6 (#56)

Knowledge benchmarks
BenchmarkClaude Opus 5Kimi K2.5
GPQA Diamond93.9%87.6%
SimpleQA Verified59.9%34.3%
LMArena Expert15571466
Humanity's Last Exam—24.4%
Vectara Hallucination Rate—14.2%

Multimodal Claude Opus 5 leads

Claude Opus 5: 50.8 (#8), Kimi K2.5: 41.1 (#39)

Multimodal benchmarks
BenchmarkClaude Opus 5Kimi K2.5
LMArena Vision13191269
LMArena Document15161430
Blueprint-Bench 230.4%—
Furniture Assembly60.8%—

Multilingual Claude Opus 5 leads

Claude Opus 5: 58.8 (#4), Kimi K2.5: 53.9 (#53)

Multilingual benchmarks
BenchmarkClaude Opus 5Kimi K2.5
LMArena Non-English15011433
LMArena Chinese15741495
LMArena French15191454
LMArena German15241441
LMArena Japanese15161421
LMArena Korean15211410
LMArena Russian15071435
LMArena Spanish15191450

Instruction Following Claude Opus 5 leads

Claude Opus 5: 79.2 (#7), Kimi K2.5: 75.3 (#64)

Instruction Following benchmarks
BenchmarkClaude Opus 5Kimi K2.5
LMArena Instruction Following15171431

Long Context Kimi K2.5 leads

Claude Opus 5: 46.5 (#21), Kimi K2.5: 52.1 (#7)

Long Context benchmarks
BenchmarkClaude Opus 5Kimi K2.5
LMArena Longer Query15151445
Fiction.LiveBench—86.1%
CL-bench—19.3%
CL-bench Life—13.2%

Writing & Preference Claude Opus 5 leads

Claude Opus 5: 79.2 (#1), Kimi K2.5: 65.1 (#53)

Writing & Preference benchmarks
BenchmarkClaude Opus 5Kimi K2.5
LMArena Text15071445
LMArena Creative Writing14911423
EQ-Bench Creative Writing21331579
LMArena Multi-Turn14991444
EQ-Bench 41385—

Frequently asked questions

Is Claude Opus 5 better than Kimi K2.5?

Claude Opus 5 is the stronger model overall, scoring 67.8 to 48.1 on the Noometry Index. Kimi K2.5 costs 11× less per token, which makes it the better buy when Claude Opus 5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 5 or Kimi K2.5?

Kimi K2.5 is cheaper. It lists at $0.45 per million input tokens and $2.25 per million output tokens; Claude Opus 5 lists at $5 and $25.

Is Claude Opus 5 or Kimi K2.5 better for coding?

Claude Opus 5 scores higher on coding benchmarks: 67.5 versus 48.8 in the Noometry coding category.

Which has the bigger context window?

Claude Opus 5 does, with 1M tokens against 262K.

How many benchmarks do Claude Opus 5 and Kimi K2.5 share?

35 benchmarks have published results for both models. Claude Opus 5 has 57 scored results on Noometry and Kimi K2.5 has 51.

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