Noometry

Model comparison

C4ai Aya Expanse 8b vs Kimi K2.5

Kimi K2.5 is the stronger model overall, scoring 48.1 to 34.9 on the Noometry Index.

Last verified . 15 shared benchmarks.

C4ai Aya Expanse 8b Cohere

34.9

Rank #229 Confirmed

Kimi K2.5 Moonshot AI

48.1

Rank #57 Confirmed

Summary

  • They share 15 benchmarks with published results for both. C4ai Aya Expanse 8b scores higher in 0 categories and Kimi K2.5 in 8 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in writing & preference, where Kimi K2.5 leads 65.1 to 39.0.

Side by side

C4ai Aya Expanse 8bKimi K2.5
ProviderCohereMoonshot AI
Noometry Index34.948.1
Released—2026-01-27
WeightsOpenOpen
Context window—262K
Max output—262K
Input $ / M tokens—$0.45
Output $ / M tokens—$2.25
Results tracked1551

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Category by category

Coding Kimi K2.5 leads

C4ai Aya Expanse 8b: 33.8 (#252), Kimi K2.5: 48.8 (#53)

BenchmarkC4ai Aya Expanse 8bKimi K2.5
LMArena Coding11601474
SWE-bench Verified—73.8%
SWE-bench Verified (bash only)—70.8%
LMArena WebDev—1437
SWE-bench Multilingual—67.3%
SciCode—49%
WeirdML—45.6%
ALE-Bench—821.65

Agentic & Tool Use Not comparable

C4ai Aya Expanse 8b: —, Kimi K2.5: 34.2 (#48)

BenchmarkC4ai Aya Expanse 8bKimi K2.5
Terminal-Bench—43.2%
OSWorld—63.3%
Vending-Bench 2—1,198

Reasoning Kimi K2.5 leads

C4ai Aya Expanse 8b: 22.4 (#197), Kimi K2.5: 31.2 (#80)

BenchmarkC4ai Aya Expanse 8bKimi K2.5
LMArena Hard Prompts11561453
ARC-AGI-2—11.8%
SimpleBench—46.8%
Kagi LLM Benchmark—78.5%
NYT Connections (extended)—69.9%
ARC-AGI-1—65.3%
CritPt—3.1%
Chess Puzzles—12%
EnigmaEval—3.4%
Thematic Generalization—69.4%
Epoch Capabilities Index—148.03

Math Kimi K2.5 leads

C4ai Aya Expanse 8b: 33.3 (#203), Kimi K2.5: 51.8 (#53)

BenchmarkC4ai Aya Expanse 8bKimi K2.5
LMArena Math11681470
MathArena Final-Answer Competitions—62.3%
OTIS Mock AIME 2024-2025—92.2%
FrontierMath (Feb 2025 set)—27.9%
FrontierMath Tier 4 (v1)—4.2%

Knowledge Kimi K2.5 leads

C4ai Aya Expanse 8b: 33.6 (#201), Kimi K2.5: 53.6 (#56)

BenchmarkC4ai Aya Expanse 8bKimi K2.5
Vectara Hallucination Rate9.5%14.2%
LMArena Expert11531466
GPQA Diamond—87.6%
Humanity's Last Exam—24.4%
SimpleQA Verified—34.3%

Multimodal Not comparable

C4ai Aya Expanse 8b: —, Kimi K2.5: 41.1 (#39)

BenchmarkC4ai Aya Expanse 8bKimi K2.5
LMArena Vision—1269
LMArena Document—1430

Multilingual Kimi K2.5 leads

C4ai Aya Expanse 8b: 36.1 (#242), Kimi K2.5: 53.9 (#53)

BenchmarkC4ai Aya Expanse 8bKimi K2.5
LMArena Non-English11801433
LMArena Chinese11811495
LMArena German11881441
LMArena Japanese11201421
LMArena Russian11971435
LMArena French—1454
LMArena Korean—1410
LMArena Spanish—1450

Instruction Following Kimi K2.5 leads

C4ai Aya Expanse 8b: 60.1 (#253), Kimi K2.5: 75.3 (#64)

BenchmarkC4ai Aya Expanse 8bKimi K2.5
LMArena Instruction Following11551431

Long Context Kimi K2.5 leads

C4ai Aya Expanse 8b: 36.1 (#236), Kimi K2.5: 52.1 (#7)

BenchmarkC4ai Aya Expanse 8bKimi K2.5
LMArena Longer Query11911445
Fiction.LiveBench—86.1%
CL-bench—19.3%
CL-bench Life—13.2%

Writing & Preference Kimi K2.5 leads

C4ai Aya Expanse 8b: 39.0 (#250), Kimi K2.5: 65.1 (#53)

BenchmarkC4ai Aya Expanse 8bKimi K2.5
LMArena Text11851445
LMArena Creative Writing11681423
LMArena Multi-Turn11601444
EQ-Bench Creative Writing—1579

Frequently asked questions

Is C4ai Aya Expanse 8b better than Kimi K2.5?

Kimi K2.5 is the stronger model overall, scoring 48.1 to 34.9 on the Noometry Index.

Is C4ai Aya Expanse 8b or Kimi K2.5 better for coding?

Kimi K2.5 scores higher on coding benchmarks: 48.8 versus 33.8 in the Noometry coding category.

How many benchmarks do C4ai Aya Expanse 8b and Kimi K2.5 share?

15 benchmarks have published results for both models. C4ai Aya Expanse 8b has 15 scored results on Noometry and Kimi K2.5 has 51.

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