Pairwise benchmark snapshot · Aug 16, 2026

GPT-4.5 Orion vs MoonshotAI: Kimi K2.5 benchmark

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

This page compares GPT-4.5 Orion (OpenAI) and MoonshotAI: Kimi K2.5 (Moonshot) using the latest snapshots we have as of Aug 16, 2026. On preference Elo, GPT-4.5 Orion is ahead by 25 points (1,540 vs 1,515; seed-bootstrap (Aug 1, 2026)). On SWE-bench coding, MoonshotAI: Kimi K2.5 resolves 71.3% versus 71% (seed-bootstrap (Aug 1, 2026)). MoonshotAI: Kimi K2.5 streams faster (72 tok/s) while MoonshotAI: Kimi K2.5 is the cheaper output token ($2.85/1M). MoonshotAI: Kimi K2.5 has the larger context window (262k 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.

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OpenAI

GPT-4.5 Orion

OpenAI largest dense non-reasoning model with expansive world knowledge and reduced hallucinations.

Elo 1,540$150/1M 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

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Model A

Model B

Quick vs:vs Claude Opus 4.5 vs Claude Opus 4.6 vs Claude Sonnet 4.5 vs Claude 3.7 Sonnet

Interactive Comparison Diagram

Matchup Breakdown

Tug-of-War Matchup Matrix

Category wins across intelligence, speed, and pricing efficiency.

GPT-4.5 Orion (2)vsMoonshotAI: Kimi K2.5 (7)

GPT-4.5 Orion: 2W (22%)Overall: MoonshotAI: Kimi K2.5MoonshotAI: Kimi K2.5: 7W (78%)

← GPT-4.5 Orion1 tiesMoonshotAI: Kimi K2.5 →

Tied (2/5)

Intelligence & Reasoning

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

Preference Elo

1,540vs1,515

Coding Elo

1,520vs1,520

SWE-bench

71%vs71.3%

LiveBench

68.5%vs67.2%

GPQA Diamond

84%vs87.6%

GPT-4.5 Orion: 2WMoonshotAI: Kimi K2.5: 2W

MoonshotAI: Kimi K2.5 (2/2)

Speed & Latency

Generation throughput and time to first token responsiveness

Output speed

60 tok/svs72 tok/s

Time to first token

350 msvs270 ms

GPT-4.5 Orion: 0WMoonshotAI: Kimi K2.5: 2W

MoonshotAI: Kimi K2.5 (3/3)

Pricing & Capacity

Cost per million tokens and max context window length

Output price

$150/1Mvs$2.85/1M

Input price

$75/1Mvs$0.57/1M

Context window

128kvs262k

GPT-4.5 Orion: 0WMoonshotAI: Kimi K2.5: 3W

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 5/6

Preference Elo

GPT-4.5 Orion

25 pts advantage

Throughput Speed

MoonshotAI: Kimi K2.5

12 tok/s faster

Price Efficiency

MoonshotAI: Kimi K2.5

$147.15/1M cheaper

Full Benchmark Score Matrix

—

Elo

High is better

+2%1,540

EloHigh is better

1,515

Code Elo

High is better

1,520

Code EloHigh is better

1,520

LiveBench

High is better

+2%68.5%

LiveBenchHigh is better

67.2%

SWE-bench

High is better

71%

SWE-benchHigh is better

71.3%

GPQA

High is better

84%

GPQAHigh is better

87.6%+4%

TTFT

Low is better

350 ms

TTFTLow is better

270 ms+30%

Speed

High is better

60 tok/s

SpeedHigh is better

72 tok/s+20%

In $

Low is better

$75/1M

In $Low is better

$0.57/1M+13058%

Out $

Low is better

$150/1M

Out $Low is better

$2.85/1M+5163%

Context

High is better

128k

ContextHigh is better

262k+105%

Interactive Simulator

Workload Cost & Savings Calculator

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

Save up to 99% 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)

GPT-4.5 Orion$4,875.00 / mo

In: $2625.00Out: $2250.00

MoonshotAI: Kimi K2.5$62.70 / mo

In: $19.95Out: $42.75

Estimated Cost Delta

MoonshotAI: Kimi K2.5 is estimated to save $4,812.30/month ($57,748/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
MoonshotAI: Kimi K2.5:Pick MoonshotAI: Kimi K2.5 when time-to-first-token matters more than peak Elo.
3
GPT-4.5 Orion:Pick GPT-4.5 Orion as the default general assistant.

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 UIMoonshotAI: Kimi K2.5

Lower TTFT (270 ms).

Long-document RAGMoonshotAI: Kimi K2.5

Larger window (262k).

Screenshots / visionGPT-4.5 Orion

Both accept images. Defaulting to the higher-Elo side (GPT-4.5 Orion).

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	MoonshotAI: Kimi K2.5	Lower TTFT (270 ms).
Long-document RAG	MoonshotAI: Kimi K2.5	Larger window (262k).
Screenshots / vision	GPT-4.5 Orion	Both accept images. Defaulting to the higher-Elo side (GPT-4.5 Orion).

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LIVE

OpenAI

GPT-4.5 Orion

Elo 1,540

LiveBench68.5%

SWE-bench71%

Speed60 tok/s

Output cost$150/1M

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, GPT-4.5 Orion or MoonshotAI: Kimi K2.5?: GPT-4.5 Orion has the higher preference Elo in our latest snapshot (1,540). “Better” still depends on coding, price, and latency — see the table.
Which is better at coding, GPT-4.5 Orion or MoonshotAI: Kimi K2.5?: MoonshotAI: Kimi K2.5 leads SWE-bench at 71.3% vs 71%. 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 $150/1M. Input prices and retry rates still move the real bill.
Which is faster, GPT-4.5 Orion or MoonshotAI: Kimi K2.5?: MoonshotAI: Kimi K2.5 has the lower time-to-first-token (270 ms vs 350 ms). Tokens/sec is a separate column if you care about long completions.
Which has the larger context window?: MoonshotAI: Kimi K2.5 accepts 262k tokens versus 128k.
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. GPT-4.5 Orion 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 GPT-4.5 Orion matchups →|All MoonshotAI: Kimi K2.5 matchups →

GPT-4.5 Orion vs OpenAI: o1 (previous gpt-flagship)GPT-4.5 Orion vs GPT-5 (next gpt-flagship)MoonshotAI: Kimi K2.5 vs MoonshotAI: Kimi K2 0711 (previous kimi)MoonshotAI: Kimi K2.5 vs Kimi K3 (next kimi)GPT-5.6 Terra vs GPT-4.5 Orion Kimi K3 vs GPT-4.5 Orion

GPT-4.5 Orion vs MoonshotAI: Kimi K2.5 benchmark

Interactive Comparison Diagram

Matchup Breakdown

Tug-of-War Matchup Matrix

Category wins across intelligence, speed, and pricing efficiency.

GPT-4.5 Orion (2)vsMoonshotAI: Kimi K2.5 (7)

GPT-4.5 Orion: 2W (22%)Overall: MoonshotAI: Kimi K2.5MoonshotAI: Kimi K2.5: 7W (78%)

← GPT-4.5 Orion1 tiesMoonshotAI: Kimi K2.5 →

Tied (2/5)

Intelligence & Reasoning

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

Preference Elo

1,540vs1,515

Coding Elo

1,520vs1,520

SWE-bench

71%vs71.3%

LiveBench

68.5%vs67.2%

GPQA Diamond

84%vs87.6%

GPT-4.5 Orion: 2WMoonshotAI: Kimi K2.5: 2W

MoonshotAI: Kimi K2.5 (2/2)

Speed & Latency

Generation throughput and time to first token responsiveness

Output speed

60 tok/svs72 tok/s

Time to first token

350 msvs270 ms

GPT-4.5 Orion: 0WMoonshotAI: Kimi K2.5: 2W

MoonshotAI: Kimi K2.5 (3/3)

Pricing & Capacity

Cost per million tokens and max context window length

Output price

$150/1Mvs$2.85/1M

Input price

$75/1Mvs$0.57/1M

Context window

128kvs262k

GPT-4.5 Orion: 0WMoonshotAI: Kimi K2.5: 3W

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 UIMoonshotAI: Kimi K2.5

Lower TTFT (270 ms).

Long-document RAGMoonshotAI: Kimi K2.5

Larger window (262k).

Screenshots / visionGPT-4.5 Orion

Both accept images. Defaulting to the higher-Elo side (GPT-4.5 Orion).

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	MoonshotAI: Kimi K2.5	Lower TTFT (270 ms).
Long-document RAG	MoonshotAI: Kimi K2.5	Larger window (262k).
Screenshots / vision	GPT-4.5 Orion	Both accept images. Defaulting to the higher-Elo side (GPT-4.5 Orion).

Frequently Asked Questions

Which is better overall, GPT-4.5 Orion or MoonshotAI: Kimi K2.5?

GPT-4.5 Orion has the higher preference Elo in our latest snapshot (1,540). “Better” still depends on coding, price, and latency — see the table.

Which is better at coding, GPT-4.5 Orion or MoonshotAI: Kimi K2.5?

MoonshotAI: Kimi K2.5 leads SWE-bench at 71.3% vs 71%. 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 $150/1M. Input prices and retry rates still move the real bill.

Which is faster, GPT-4.5 Orion or MoonshotAI: Kimi K2.5?

MoonshotAI: Kimi K2.5 has the lower time-to-first-token (270 ms vs 350 ms). Tokens/sec is a separate column if you care about long completions.

Which has the larger context window?

MoonshotAI: Kimi K2.5 accepts 262k tokens versus 128k.

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. GPT-4.5 Orion and MoonshotAI: Kimi K2.5 Elo cells are dated snapshots from the named source — we do not compute Arena ourselves.