Pairwise benchmark snapshot · Aug 16, 2026

GPT-5.6 Luna vs Kimi K3 benchmark

Name: GPT-5.6 Luna vs Kimi K3 AI benchmark comparison
Creator: CompareLLM
License: https://creativecommons.org/licenses/by/4.0/

This page compares GPT-5.6 Luna (OpenAI) and Kimi K3 (Moonshot) using the latest snapshots we have as of Aug 16, 2026. On preference Elo, Kimi K3 is ahead by 62 points (1,528 vs 1,466; seed-bootstrap (Aug 1, 2026)). On SWE-bench coding, Kimi K3 resolves 73.8% versus 61.8% (seed-bootstrap (Aug 1, 2026)). GPT-5.6 Luna streams faster (188 tok/s) while GPT-5.6 Luna is the cheaper output token ($0.6/1M). GPT-5.6 Luna has the larger context window (1.1M 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

OpenAI

GPT-5.6 Luna

OpenAI 5.6 fast/cheap tier. Official API $0.20/$1.20 per 1M after the Jul 30 80% Luna cut.

Elo 1,466$0.6/1M out

Moonshot

Kimi K3

Moonshot AI frontier flagship reasoning and agent swarm model with 256k context and top-tier SWE-bench coding capability.

Elo 1,528$15/1M 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 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-5.6 Luna (5)vsKimi K3 (5)

GPT-5.6 Luna: 5W (50%)Overall: Even matchupKimi K3: 5W (50%)

← GPT-5.6 LunaKimi K3 →

Kimi K3 (5/5)

Intelligence & Reasoning

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

Preference Elo

1,466vs1,528

Coding Elo

1,458vs1,535

SWE-bench

61.8%vs73.8%

LiveBench

64.2%vs69.5%

GPQA Diamond

75.4%vs88.4%

GPT-5.6 Luna: 0WKimi K3: 5W

GPT-5.6 Luna (2/2)

Speed & Latency

Generation throughput and time to first token responsiveness

Output speed

188 tok/svs68 tok/s

Time to first token

88 msvs290 ms

GPT-5.6 Luna: 2WKimi K3: 0W

GPT-5.6 Luna (3/3)

Pricing & Capacity

Cost per million tokens and max context window length

Output price

$0.6/1Mvs$15/1M

Input price

$0.1/1Mvs$3/1M

Context window

1.1Mvs1M

GPT-5.6 Luna: 3WKimi K3: 0W

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 AdvantageEven 3–3

Preference Elo

Kimi K3

62 pts advantage

Throughput Speed

GPT-5.6 Luna

120 tok/s faster

Price Efficiency

GPT-5.6 Luna

$14.40/1M cheaper

Full Benchmark Score Matrix

—

Elo

High is better

1,466

EloHigh is better

1,528+4%

Code Elo

High is better

1,458

Code EloHigh is better

1,535+5%

LiveBench

High is better

64.2%

LiveBenchHigh is better

69.5%+8%

SWE-bench

High is better

61.8%

SWE-benchHigh is better

73.8%+19%

GPQA

High is better

75.4%

GPQAHigh is better

88.4%+17%

TTFT

Low is better

+230%88 ms

TTFTLow is better

290 ms

Speed

High is better

+176%188 tok/s

SpeedHigh is better

68 tok/s

In $

Low is better

+2900%$0.1/1M

In $Low is better

$3/1M

Out $

Low is better

+2400%$0.6/1M

Out $Low is better

$15/1M

Context

High is better

1.1M

ContextHigh is better

Interactive Simulator

Workload Cost & Savings Calculator

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

Save up to 96% with GPT-5.6 Luna

Monthly Volume50M tokens/mo

Quick Presets:

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

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

GPT-5.6 Luna$12.50 / mo

In: $3.50Out: $9.00

Kimi K3$330.00 / mo

In: $105.00Out: $225.00

Estimated Cost Delta

GPT-5.6 Luna is estimated to save $317.50/month ($3,810/year).

Based on 50M tokens (30% gen)

Key Selection Recommendations

1
Kimi K3:Pick Kimi K3 when repo-level coding accuracy is the constraint.
2
GPT-5.6 Luna:Pick GPT-5.6 Luna when you are optimizing output cost.
3
GPT-5.6 Luna:Pick GPT-5.6 Luna when time-to-first-token matters more than peak Elo.

Recommended Workload Routing

Repo / coding agentsKimi K3

Higher SWE-bench (73.8%).

High-volume chatGPT-5.6 Luna

Lower output list price ($0.6/1M).

Voice / low-latency UIGPT-5.6 Luna

Lower TTFT (88 ms).

Long-document RAGGPT-5.6 Luna

Larger window (1.1M).

Screenshots / visionKimi K3

Both accept images. Defaulting to the higher-Elo side (Kimi K3).

Target Workload	Recommended Pick	Evaluation Rationale
Repo / coding agents	Kimi K3	Higher SWE-bench (73.8%).
High-volume chat	GPT-5.6 Luna	Lower output list price ($0.6/1M).
Voice / low-latency UI	GPT-5.6 Luna	Lower TTFT (88 ms).
Long-document RAG	GPT-5.6 Luna	Larger window (1.1M).
Screenshots / vision	Kimi K3	Both accept images. Defaulting to the higher-Elo side (Kimi K3).

Related Editorial Dispatches & Benchmark Notes

View all news

priceJul 30, 2026

GPT-5.6 Luna’s 80% cut: $0.20/$1.20 for volume chat

Luna is the OpenAI fast/cheap 5.6 SKU after Jul 30. It is not Sol. Sort by price and TTFT, not Elo.

launchJun 8, 2026

Kimi K3: Moonshot’s long-context open-weight competitive row

Jun 2026. The Kimi vs GPT hub remaps to the top Moonshot Elo vs top OpenAI Elo.

launchAug 8, 2025

GPT-5 mini: the 2025 distill still useful as a cheap OpenAI baseline

High-volume agents that cannot pay Sol. Compare to Luna before you assume the new cheap SKU wins.

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/gpt-5-6-luna-vs-kimi-k3/opengraph-image for crawlers.

PNG

CompareLLM Matrix

Verified head-to-head card

LIVE

OpenAI

GPT-5.6 Luna

Elo 1,466

LiveBench64.2%

SWE-bench61.8%

Speed188 tok/s

Output cost$0.6/1M

Moonshot

Kimi K3

Elo 1,528

LiveBench69.5%

SWE-bench73.8%

Speed68 tok/s

Output cost$15/1M

Frequently Asked Questions

Which is better overall, GPT-5.6 Luna or Kimi K3?: Kimi K3 has the higher preference Elo in our latest snapshot (1,528). “Better” still depends on coding, price, and latency — see the table.
Which is better at coding, GPT-5.6 Luna or Kimi K3?: Kimi K3 leads SWE-bench at 73.8% vs 61.8%. SWE-bench is one harness, not your repo.
Which is cheaper to run in production?: GPT-5.6 Luna output tokens are $0.6/1M versus $15/1M. Input prices and retry rates still move the real bill.
Which is faster, GPT-5.6 Luna or Kimi K3?: GPT-5.6 Luna has the lower time-to-first-token (88 ms vs 290 ms). Tokens/sec is a separate column if you care about long completions.
Which has the larger context window?: GPT-5.6 Luna accepts 1.1M tokens versus 1M.
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-5.6 Luna and Kimi K3 Elo cells are dated snapshots from the named source — we do not compute Arena ourselves.

Similar Head-to-Head Comparisons

All GPT-5.6 Luna matchups →|All Kimi K3 matchups →

GPT-5.6 Luna vs GPT-5 mini (previous gpt-mini)Kimi K3 vs MoonshotAI: Kimi K2.5 (previous kimi)GPT-4.5 Orion vs Kimi K3 GPT-5.6 Terra vs Kimi K3 GPT-5 vs Kimi K3 GPT-5.6 Sol vs Kimi K3

GPT-5.6 Luna vs Kimi K3 benchmark

Interactive Comparison Diagram

Matchup Breakdown

Tug-of-War Matchup Matrix

Category wins across intelligence, speed, and pricing efficiency.

GPT-5.6 Luna (5)vsKimi K3 (5)

GPT-5.6 Luna: 5W (50%)Overall: Even matchupKimi K3: 5W (50%)

← GPT-5.6 LunaKimi K3 →

Kimi K3 (5/5)

Intelligence & Reasoning

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

Preference Elo

1,466vs1,528

Coding Elo

1,458vs1,535

SWE-bench

61.8%vs73.8%

LiveBench

64.2%vs69.5%

GPQA Diamond

75.4%vs88.4%

GPT-5.6 Luna: 0WKimi K3: 5W

GPT-5.6 Luna (2/2)

Speed & Latency

Generation throughput and time to first token responsiveness

Output speed

188 tok/svs68 tok/s

Time to first token

88 msvs290 ms

GPT-5.6 Luna: 2WKimi K3: 0W

GPT-5.6 Luna (3/3)

Pricing & Capacity

Cost per million tokens and max context window length

Output price

$0.6/1Mvs$15/1M

Input price

$0.1/1Mvs$3/1M

Context window

1.1Mvs1M

GPT-5.6 Luna: 3WKimi K3: 0W

Recommended Workload Routing

Repo / coding agentsKimi K3

Higher SWE-bench (73.8%).

High-volume chatGPT-5.6 Luna

Lower output list price ($0.6/1M).

Voice / low-latency UIGPT-5.6 Luna

Lower TTFT (88 ms).

Long-document RAGGPT-5.6 Luna

Larger window (1.1M).

Screenshots / visionKimi K3

Both accept images. Defaulting to the higher-Elo side (Kimi K3).

Target Workload	Recommended Pick	Evaluation Rationale
Repo / coding agents	Kimi K3	Higher SWE-bench (73.8%).
High-volume chat	GPT-5.6 Luna	Lower output list price ($0.6/1M).
Voice / low-latency UI	GPT-5.6 Luna	Lower TTFT (88 ms).
Long-document RAG	GPT-5.6 Luna	Larger window (1.1M).
Screenshots / vision	Kimi K3	Both accept images. Defaulting to the higher-Elo side (Kimi K3).

Frequently Asked Questions

Which is better overall, GPT-5.6 Luna or Kimi K3?

Kimi K3 has the higher preference Elo in our latest snapshot (1,528). “Better” still depends on coding, price, and latency — see the table.

Which is better at coding, GPT-5.6 Luna or Kimi K3?

Kimi K3 leads SWE-bench at 73.8% vs 61.8%. SWE-bench is one harness, not your repo.

Which is cheaper to run in production?

GPT-5.6 Luna output tokens are $0.6/1M versus $15/1M. Input prices and retry rates still move the real bill.

Which is faster, GPT-5.6 Luna or Kimi K3?

GPT-5.6 Luna has the lower time-to-first-token (88 ms vs 290 ms). Tokens/sec is a separate column if you care about long completions.

Which has the larger context window?

GPT-5.6 Luna accepts 1.1M tokens versus 1M.

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-5.6 Luna and Kimi K3 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

Kimi K3

GPT-5.6 Luna

GPT-5.6 Luna

Full Benchmark Score Matrix

Workload Cost & Savings Calculator

Key Selection Recommendations

Recommended Workload Routing

Related Editorial Dispatches & Benchmark Notes

GPT-5.6 Luna’s 80% cut: $0.20/$1.20 for volume chat

Kimi K3: Moonshot’s long-context open-weight competitive row

GPT-5 mini: the 2025 distill still useful as a cheap OpenAI baseline

Cast Your Matchup Vote

Community Discussions (0)

Share card

CompareLLM Matrix

GPT-5.6 Luna

Kimi K3

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

Kimi K3

GPT-5.6 Luna

GPT-5.6 Luna

Full Benchmark Score Matrix

Workload Cost & Savings Calculator

Key Selection Recommendations

Recommended Workload Routing

Related Editorial Dispatches & Benchmark Notes

GPT-5.6 Luna’s 80% cut: $0.20/$1.20 for volume chat

Kimi K3: Moonshot’s long-context open-weight competitive row

GPT-5 mini: the 2025 distill still useful as a cheap OpenAI baseline

Cast Your Matchup Vote

Community Discussions (0)

Share card

CompareLLM Matrix

GPT-5.6 Luna

Kimi K3

Frequently Asked Questions

Related news

Similar Head-to-Head Comparisons