Pairwise benchmark snapshot · Aug 16, 2026

Claude Sonnet 4.5 vs MoonshotAI: Kimi K2.5 benchmark

Name: Claude Sonnet 4.5 vs MoonshotAI: Kimi K2.5 AI benchmark comparison
Creator: CompareLLM
License: https://creativecommons.org/licenses/by/4.0/

This page compares Claude Sonnet 4.5 (Anthropic) and MoonshotAI: Kimi K2.5 (Moonshot) using the latest snapshots we have as of Aug 16, 2026. On preference Elo, Claude Sonnet 4.5 is ahead by 9 points (1,524 vs 1,515; seed-bootstrap (Aug 1, 2026)). On SWE-bench coding, MoonshotAI: Kimi K2.5 resolves 71.3% versus 70.1% (seed-bootstrap (Aug 1, 2026)). Claude Sonnet 4.5 streams faster (88 tok/s) while MoonshotAI: Kimi K2.5 is the cheaper output token ($2.85/1M). Claude Sonnet 4.5 has the larger context window (1M tokens). Every cell below is a dated snapshot from a named public source — we do not invent missing scores, and we do not run SWE-bench ourselves.

Share Analysis:

WhatsApp Telegram X / Post LinkedIn Reddit

Anthropic

Claude Sonnet 4.5

Workhorse Anthropic model: most of Opus coding quality at a mid-tier price.

Elo 1,524$15/1M out

Moonshot

MoonshotAI: Kimi K2.5

Auto-discovered from OpenRouter (moonshotai/kimi-k2.5). Preview until a second source matches.

Elo 1,515$2.8499999999999996/1M out

Swap or Add Any Model to this Matchup

Instant pairwise benchmark recalculation across 400+ LLMs

Model A

Model B

Quick vs:vs Claude Opus 4.5 vs Claude Opus 4.6 vs Claude 3.7 Sonnet vs GPT-5

Interactive Comparison Diagram

Matchup Breakdown

Tug-of-War Matchup Matrix

Category wins across intelligence, speed, and pricing efficiency.

Claude Sonnet 4.5 (6)vsMoonshotAI: Kimi K2.5 (4)

Claude Sonnet 4.5: 6W (60%)Overall: Claude Sonnet 4.5MoonshotAI: Kimi K2.5: 4W (40%)

← Claude Sonnet 4.5MoonshotAI: Kimi K2.5 →

Claude Sonnet 4.5 (3/5)

Intelligence & Reasoning

Preference Elo, Coding proficiency, SWE-bench & LiveBench accuracy

Preference Elo

1,524vs1,515

Coding Elo

1,531vs1,520

SWE-bench

70.1%vs71.3%

LiveBench

67.4%vs67.2%

GPQA Diamond

80.2%vs87.6%

Claude Sonnet 4.5: 3WMoonshotAI: Kimi K2.5: 2W

Claude Sonnet 4.5 (2/2)

Speed & Latency

Generation throughput and time to first token responsiveness

Output speed

88 tok/svs72 tok/s

Time to first token

240 msvs270 ms

Claude Sonnet 4.5: 2WMoonshotAI: Kimi K2.5: 0W

MoonshotAI: Kimi K2.5 (2/3)

Pricing & Capacity

Cost per million tokens and max context window length

Output price

$15/1Mvs$2.85/1M

Input price

$3/1Mvs$0.57/1M

Context window

1Mvs262k

Claude Sonnet 4.5: 1WMoonshotAI: Kimi K2.5: 2W

Capability Matchup Radar

Multi-Dimensional Capability Radar

Each spoke is a skill. Farther from the center is better (0–100th percentile). Tap any dot to inspect details.

Tap any node to inspect

Percentile 0–100

Dimensional AdvantageMoonshotAI: Kimi K2.5 4/6

Preference Elo

Claude Sonnet 4.5

9 pts advantage

Throughput Speed

Claude Sonnet 4.5

16 tok/s faster

Price Efficiency

MoonshotAI: Kimi K2.5

$12.15/1M cheaper

Full Benchmark Score Matrix

—

Elo

High is better

+1%1,524

EloHigh is better

1,515

Code Elo

High is better

+1%1,531

Code EloHigh is better

1,520

LiveBench

High is better

67.4%

LiveBenchHigh is better

67.2%

SWE-bench

High is better

70.1%

SWE-benchHigh is better

71.3%+2%

GPQA

High is better

80.2%

GPQAHigh is better

87.6%+9%

TTFT

Low is better

+13%240 ms

TTFTLow is better

270 ms

Speed

High is better

+22%88 tok/s

SpeedHigh is better

72 tok/s

In $

Low is better

$3/1M

In $Low is better

$0.57/1M+426%

Out $

Low is better

$15/1M

Out $Low is better

$2.85/1M+426%

Context

High is better

+281%1M

ContextHigh is better

262k

Interactive Simulator

Workload Cost & Savings Calculator

Simulate monthly production API costs based on published $/1M tokens.

Save up to 81% with MoonshotAI: Kimi K2.5

Monthly Volume50M tokens/mo

Quick Presets:

Token Ratio (In vs Out)70% In / 30% Out

RAG / Search (10% out)Coding / Chat (50% out)

Claude Sonnet 4.5$330.00 / mo

In: $105.00Out: $225.00

MoonshotAI: Kimi K2.5$62.70 / mo

In: $19.95Out: $42.75

Estimated Cost Delta

MoonshotAI: Kimi K2.5 is estimated to save $267.30/month ($3,208/year).

Based on 50M tokens (30% gen)

Key Selection Recommendations

1
MoonshotAI: Kimi K2.5:Pick MoonshotAI: Kimi K2.5 when repo-level coding accuracy is the constraint.
2
Claude Sonnet 4.5:Pick Claude Sonnet 4.5 when time-to-first-token matters more than peak Elo.
3
Claude Sonnet 4.5:Pick Claude Sonnet 4.5 for million-token RAG or long-document jobs.

Recommended Workload Routing

Repo / coding agentsMoonshotAI: Kimi K2.5

Higher SWE-bench (71.3%).

High-volume chatMoonshotAI: Kimi K2.5

Lower output list price ($2.85/1M).

Voice / low-latency UIClaude Sonnet 4.5

Lower TTFT (240 ms).

Long-document RAGClaude Sonnet 4.5

Larger window (1M).

Screenshots / visionClaude Sonnet 4.5

Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4.5).

Target Workload	Recommended Pick	Evaluation Rationale
Repo / coding agents	MoonshotAI: Kimi K2.5	Higher SWE-bench (71.3%).
High-volume chat	MoonshotAI: Kimi K2.5	Lower output list price ($2.85/1M).
Voice / low-latency UI	Claude Sonnet 4.5	Lower TTFT (240 ms).
Long-document RAG	Claude Sonnet 4.5	Larger window (1M).
Screenshots / vision	Claude Sonnet 4.5	Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4.5).

Related Editorial Dispatches & Benchmark Notes

View all news

launchFeb 18, 2026

Claude Sonnet 4.5 is the previous workhorse — still a valid vs baseline

Most of Opus 4.5 coding at a mid-tier price. Sonnet 5 replaced it as the buy; 4.5 remains a compare baseline.

Community Sentiment

Cast Your Matchup Vote

0 total votes

Community Discussions (0)

No comments posted on this matchup yet. Be the first to share an evaluation note!

Share card

The real PNG is generated at /compare/claude-sonnet-4-5-vs-kimi-k2-5/opengraph-image for crawlers.

PNG

CompareLLM Matrix

Verified head-to-head card

LIVE

Anthropic

Claude Sonnet 4.5

Elo 1,524

LiveBench67.4%

SWE-bench70.1%

Speed88 tok/s

Output cost$15/1M

Moonshot

MoonshotAI: Kimi K2.5

Elo 1,515

LiveBench67.2%

SWE-bench71.3%

Speed72 tok/s

Output cost$2.85/1M

Frequently Asked Questions

Which is better overall, Claude Sonnet 4.5 or MoonshotAI: Kimi K2.5?: Claude Sonnet 4.5 has the higher preference Elo in our latest snapshot (1,524). “Better” still depends on coding, price, and latency — see the table.
Which is better at coding, Claude Sonnet 4.5 or MoonshotAI: Kimi K2.5?: MoonshotAI: Kimi K2.5 leads SWE-bench at 71.3% vs 70.1%. SWE-bench is one harness, not your repo.
Which is cheaper to run in production?: MoonshotAI: Kimi K2.5 output tokens are $2.85/1M versus $15/1M. Input prices and retry rates still move the real bill.
Which is faster, Claude Sonnet 4.5 or MoonshotAI: Kimi K2.5?: Claude Sonnet 4.5 has the lower time-to-first-token (240 ms vs 270 ms). Tokens/sec is a separate column if you care about long completions.
Which has the larger context window?: Claude Sonnet 4.5 accepts 1M tokens versus 262k.
Can I self-host either model?: Neither model is marked open-weights here. You are comparing hosted APIs.
Are these scores from CompareLLM’s own evals?: No. V1 aggregates public leaderboards (and optional first-party latency pings). Each cell names its source and date. Read /methodology.
What does preference Elo mean on this page?: Preference Elo is a crowd vote from LMArena / Arena. People see two hidden answers and pick the one they like more. The model that wins more often gets a higher Elo. That means people preferred it — not that it passed a school test. It is not SWE-bench, not accuracy, and not a number we invent. Claude Sonnet 4.5 and MoonshotAI: Kimi K2.5 Elo cells are dated snapshots from the named source — we do not compute Arena ourselves.

Similar Head-to-Head Comparisons

All Claude Sonnet 4.5 matchups →|All MoonshotAI: Kimi K2.5 matchups →

Claude Sonnet 4.5 vs Claude Sonnet 4 (previous sonnet)Claude Sonnet 4.5 vs Claude Sonnet 5 (next sonnet)MoonshotAI: Kimi K2.5 vs MoonshotAI: Kimi K2 0711 (previous kimi)MoonshotAI: Kimi K2.5 vs Kimi K3 (next kimi)Kimi K3 vs Claude Sonnet 4.5 Claude Opus 4.5 vs Claude Sonnet 4.5

Claude Sonnet 4.5 vs MoonshotAI: Kimi K2.5 benchmark

Interactive Comparison Diagram

Matchup Breakdown

Tug-of-War Matchup Matrix

Category wins across intelligence, speed, and pricing efficiency.

Claude Sonnet 4.5 (6)vsMoonshotAI: Kimi K2.5 (4)

Claude Sonnet 4.5: 6W (60%)Overall: Claude Sonnet 4.5MoonshotAI: Kimi K2.5: 4W (40%)

← Claude Sonnet 4.5MoonshotAI: Kimi K2.5 →

Claude Sonnet 4.5 (3/5)

Intelligence & Reasoning

Preference Elo, Coding proficiency, SWE-bench & LiveBench accuracy

Preference Elo

1,524vs1,515

Coding Elo

1,531vs1,520

SWE-bench

70.1%vs71.3%

LiveBench

67.4%vs67.2%

GPQA Diamond

80.2%vs87.6%

Claude Sonnet 4.5: 3WMoonshotAI: Kimi K2.5: 2W

Claude Sonnet 4.5 (2/2)

Speed & Latency

Generation throughput and time to first token responsiveness

Output speed

88 tok/svs72 tok/s

Time to first token

240 msvs270 ms

Claude Sonnet 4.5: 2WMoonshotAI: Kimi K2.5: 0W

MoonshotAI: Kimi K2.5 (2/3)

Pricing & Capacity

Cost per million tokens and max context window length

Output price

$15/1Mvs$2.85/1M

Input price

$3/1Mvs$0.57/1M

Context window

1Mvs262k

Claude Sonnet 4.5: 1WMoonshotAI: Kimi K2.5: 2W

Recommended Workload Routing

Repo / coding agentsMoonshotAI: Kimi K2.5

Higher SWE-bench (71.3%).

High-volume chatMoonshotAI: Kimi K2.5

Lower output list price ($2.85/1M).

Voice / low-latency UIClaude Sonnet 4.5

Lower TTFT (240 ms).

Long-document RAGClaude Sonnet 4.5

Larger window (1M).

Screenshots / visionClaude Sonnet 4.5

Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4.5).

Target Workload	Recommended Pick	Evaluation Rationale
Repo / coding agents	MoonshotAI: Kimi K2.5	Higher SWE-bench (71.3%).
High-volume chat	MoonshotAI: Kimi K2.5	Lower output list price ($2.85/1M).
Voice / low-latency UI	Claude Sonnet 4.5	Lower TTFT (240 ms).
Long-document RAG	Claude Sonnet 4.5	Larger window (1M).
Screenshots / vision	Claude Sonnet 4.5	Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4.5).

Frequently Asked Questions

Which is better overall, Claude Sonnet 4.5 or MoonshotAI: Kimi K2.5?

Claude Sonnet 4.5 has the higher preference Elo in our latest snapshot (1,524). “Better” still depends on coding, price, and latency — see the table.

Which is better at coding, Claude Sonnet 4.5 or MoonshotAI: Kimi K2.5?

MoonshotAI: Kimi K2.5 leads SWE-bench at 71.3% vs 70.1%. SWE-bench is one harness, not your repo.

Which is cheaper to run in production?

MoonshotAI: Kimi K2.5 output tokens are $2.85/1M versus $15/1M. Input prices and retry rates still move the real bill.

Which is faster, Claude Sonnet 4.5 or MoonshotAI: Kimi K2.5?

Claude Sonnet 4.5 has the lower time-to-first-token (240 ms vs 270 ms). Tokens/sec is a separate column if you care about long completions.

Which has the larger context window?

Claude Sonnet 4.5 accepts 1M tokens versus 262k.

Can I self-host either model?

Neither model is marked open-weights here. You are comparing hosted APIs.

Are these scores from CompareLLM’s own evals?

No. V1 aggregates public leaderboards (and optional first-party latency pings). Each cell names its source and date. Read /methodology.

What does preference Elo mean on this page?

Preference Elo is a crowd vote from LMArena / Arena. People see two hidden answers and pick the one they like more. The model that wins more often gets a higher Elo. That means people preferred it — not that it passed a school test. It is not SWE-bench, not accuracy, and not a number we invent. Claude Sonnet 4.5 and MoonshotAI: Kimi K2.5 Elo cells are dated snapshots from the named source — we do not compute Arena ourselves.

Swap or Add Any Model to this Matchup

Interactive Comparison Diagram

Tug-of-War Matchup Matrix

Intelligence & Reasoning

Speed & Latency

Pricing & Capacity

Multi-Dimensional Capability Radar

Claude Sonnet 4.5

Claude Sonnet 4.5

MoonshotAI: Kimi K2.5

Full Benchmark Score Matrix

Workload Cost & Savings Calculator

Key Selection Recommendations

Recommended Workload Routing

Related Editorial Dispatches & Benchmark Notes

Claude Sonnet 4.5 is the previous workhorse — still a valid vs baseline

Cast Your Matchup Vote

Community Discussions (0)

Share card

CompareLLM Matrix

Claude Sonnet 4.5

MoonshotAI: Kimi K2.5

Frequently Asked Questions

Related news

Similar Head-to-Head Comparisons

Swap or Add Any Model to this Matchup

Interactive Comparison Diagram

Tug-of-War Matchup Matrix

Intelligence & Reasoning

Speed & Latency

Pricing & Capacity

Multi-Dimensional Capability Radar

Claude Sonnet 4.5

Claude Sonnet 4.5

MoonshotAI: Kimi K2.5

Full Benchmark Score Matrix

Workload Cost & Savings Calculator

Key Selection Recommendations

Recommended Workload Routing

Related Editorial Dispatches & Benchmark Notes

Claude Sonnet 4.5 is the previous workhorse — still a valid vs baseline

Cast Your Matchup Vote

Community Discussions (0)

Share card

CompareLLM Matrix

Claude Sonnet 4.5

MoonshotAI: Kimi K2.5

Frequently Asked Questions

Related news

Similar Head-to-Head Comparisons