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Van Data Team

text model comparison

GPT-6 Luna vs Kimi K3

GPT-6 Luna and Kimi K3 are both current text models, from OpenAI and Moonshot Kimi. GPT-6 Luna is 97% cheaper per 1M input tokens than Kimi K3, $0.10 vs $3. On Arena Text, GPT-6 Luna scores 1443 Elo and Kimi K3 1488 Elo (Arena, measured October 8, 2026). Both accept about 1.05M tokens of context (1,050,000 and 1,048,576).

Higher Arena Text
Kimi K31488 Elo against 1443 Elo
Lower price per 1M input tokens
GPT-6 Luna$0.10 against $3
Longer context window
GPT-6 Luna1.05M tokens against 1.05M tokens
Newer release
GPT-6 LunaSep 2026 against Jul 2026

Data verified October 28, 2026 · Dataset 2026-10-28

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Side by side

GPT-6 Luna and Kimi K3, line by line

Prices in effect today, compared at the same tier wherever both list one. The better value in each row is highlighted.

FactGPT-6 LunaKimi K3
Price
Price per 1M input tokens$0.10 (better)$3
Price per 1M output tokens$0.50 (better)$15
Independent benchmarks
Arena Text1443 Elo (#37 of 49)1488 Elo (#8 of 49) (better)
GPQA Diamond90.5% (#25 of 40)93.1% (#15 of 40) (better)
FrontierMath Tiers 1-3 (v2)78.9% (#14 of 40) (better)72.2% (#19 of 40)
SimpleQA Verified41.4% (#26 of 36)50.6% (#19 of 36) (better)
Specs
ProviderOpenAIMoonshot Kimi
Release dateSeptember 22, 2026July 16, 2026
AccessAPI onlyAPI and open weights
Context window1,050,000 tokens1,048,576 tokens
Max output128,000 tokensNot reported
Inputtext, imagetext, image
Outputtexttext

Scores:Arena · 2026-10-12Epoch AI · 2026-10-12

Open both in the interactive comparison

Charts

Against every current text model

Where GPT-6 Luna and Kimi K3 land among the current models of their task, on every independent benchmark, on price and on context.

Where each stands

On Arena Text, GPT-6 Luna ranks #37 and Kimi K3 #8 of 49 current models. Each bar is the share of current models it beats: on score, price and context.

GPT-6 Luna and Kimi K3 among the current text models, one row per benchmark, price and context window.

Independent benchmarks

Arena Text

GPT-6 Luna:#37of 49

1,443 Elo · ahead of 23%

Kimi K3:#8of 49

1,488 Elo · ahead of 85%

GPQA Diamond

GPT-6 Luna:#25of 40

90.5% · ahead of 36%

Kimi K3:#15of 40

93.1% · ahead of 64%

FrontierMath Tiers 1-3 (v2)

GPT-6 Luna:#14of 40

78.9% · ahead of 67%

Kimi K3:#19of 40

72.2% · ahead of 54%

SimpleQA Verified

GPT-6 Luna:#26of 36

41.4% · ahead of 29%

Kimi K3:#19of 36

50.6% · ahead of 49%

Price and context

Price per 1M input tokens

GPT-6 Luna:#1of 51

$0.10 · cheaper than 96%

Kimi K3:#41of 51

$3 · cheaper than 20%

Price per 1M output tokens

GPT-6 Luna:#3of 51

$0.50 · cheaper than 92%

Kimi K3:#40of 51

$15 · cheaper than 20%

Context window

GPT-6 Luna:#1of 66

1.05M tokens · longer than 86%

Kimi K3:#11of 66

1.05M tokens · longer than 65%

Scores fromArena · 2026-10-12Epoch AI · 2026-10-12

Quality against price

Arena Text · measured October 8, 2026

GPT-6 Luna scores 1,443 at $0.2; Kimi K3 scores 1,488 at $6 (blended price per 1M tokens). The line joins the current models no other beats on both price and Arena Text score; hover any point to name it.

Quality against priceArena Text score against price for 41 text models, GPT-6 Luna and Kimi K3 marked.1,2501,3001,3501,4001,4501,5001,550$0.30$1$3$10MOST ATTRACTIVE QUADRANTMedian price $3Median 1,475Blended price per 1M tokens (3 input : 1 output), log scaleArena Text (Elo)Kimi K3GPT-6 Luna
Quality against price: the data
Arena Text score against price for 41 text models, GPT-6 Luna and Kimi K3 marked.
ModelProviderBlended price per 1M tokensArena Text (Elo)
Gemini 4 ArgonGoogle$41,525
Claude Opus 5.5Anthropic$81,507
Claude Fable 5Anthropic$201,504
Claude Fable 5.1Anthropic$201,501
Gemini 3.8 FlashGoogle$1.501,497
Muse Spark 1.3Meta$21,494
Claude Opus 5Anthropic$101,490
Kimi K3Moonshot Kimi$61,488
Gemini 3.7 FlashGoogle$1.501,486
GPT-5.6 SolOpenAI$81,485
GPT-6.1 SolOpenAI$41,484
Qwen3.8-MaxAlibaba Qwen$31,483
GPT-5.5OpenAI$111,482
Gemini 3.6 FlashGoogle$31,482
Claude Opus 4.8Anthropic$101,481
MiMo-V2.6-ProXiaomi MiMo$0.541,480
GLM-5.3Z.ai$2.151,478
Claude Sonnet 5.5Anthropic$41,476
GPT-5.4OpenAI$5.631,475
GPT-6 AstraOpenAI$201,475
DeepSeek-V4.1-FlashDeepSeek$0.521,475
GLM-5.3-FlashZ.ai$0.241,475
Gemini 3 Flash PreviewGoogle$1.131,473
Grok 4.20xAI$1.561,472
GPT-5.6 TerraOpenAI$4.501,466
Grok 4.5xAI$31,466
DeepSeek-V4-ProDeepSeek$1.981,465
Claude Sonnet 5Anthropic$41,461
GPT-6 SolOpenAI$41,456
Gemini 3.5 Flash-LiteGoogle$0.851,455
Grok 4.6xAI$31,454
GPT-5.6 LunaOpenAI$0.451,452
MiMo-V2.6-FlashXiaomi MiMo$0.181,451
GPT-6 LunaOpenAI$0.201,443
Grok 4.7xAI$31,443
Grok 4.3xAI$1.561,442
Mistral Large 4Mistral AI$2.061,429
GPT-4.1OpenAI$3.501,415
Solar Pro 4Upstage$0.521,386
GPT-4.1 miniOpenAI$0.701,383
GPT-4.1 nanoOpenAI$0.181,322

Cost

What each costs

Example workloads at each provider's listed rates, then every other rate either one lists. The cheaper figure in each row is highlighted.

The same work, priced

For 10M input and 2M output tokens, Kimi K3 costs 30 times as much as GPT-6 Luna, at each provider's listed rates.

What GPT-6 Luna and Kimi K3cost for the same work, at each provider's listed rates.

  • 10M input and 2M output tokens

    Kimi K3 costs 30× as much

    GPT-6 Luna
    $2
    Kimi K3
    $60

  • The same, with 9M of the input tokens cached

    Kimi K3 costs 30× as much

    GPT-6 Luna
    $1.19
    Kimi K3
    $35.70
Workload or rateGPT-6 LunaKimi K3
Example workloads
10M input and 2M output tokens$2 (better)$60
The same, with 9M of the input tokens cached$1.19 (better)$35.70
Other listed rates
1M input tokens, cached$0.01 (better)$0.30
1M input tokens, prompts over 272K tokens$0.20Not listed
1M output tokens, prompts over 272K tokens$0.75Not listed

Verdict

When to choose each

GPT-6 Luna

Where it leads

  • Lower input and output prices, $0.10 and $0.50 vs $3 and $15 per 1M tokens
  • Higher FrontierMath Tiers 1-3 (v2) score, 78.9% vs 72.2%
  • Cheaper cached input, $0.01 vs $0.30 per 1M tokens

Best for

  • High-volume summarisation, extraction and routing
  • Long-context budget work, where the 272k threshold is more forgiving than Haiku 5.5's 100k

Watch out for

  • Prompts over 272,000 tokens are rebilled at $0.20 input and $0.75 output for the whole request
  • A twentieth of GPT-6 Sol's price reflects a capability gap, not a discount on the same model
Full GPT-6 Luna profile

Kimi K3

Where it leads

  • Higher Arena Text score, 1488 Elo vs 1443 Elo
  • Higher GPQA Diamond score, 93.1% vs 90.5%
  • Higher SimpleQA Verified score, 50.6% vs 41.4%
  • Open weights you can run yourself

Best for

  • Teams that want a frontier-scale model they can also self-host, with one architecture across both paths
  • Long-context work at mid-tier hosted pricing

Watch out for

  • Hosted rates match Claude Sonnet 5 exactly at $3 / $15 while offering a larger context window, so the comparison turns on capability rather than price
  • Running the open weights shifts cost to infrastructure, which the token rates recorded here do not represent
  • Moonshot’s self-reported results place it ahead of Claude Opus 4.8 and GPT-5.5 but behind Claude Fable 5 and GPT-5.6 Sol; none of this was reproduced independently here
Full Kimi K3 profile

From benchmark to production

Building on GPT-6 Luna or Kimi K3?

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FAQ

GPT-6 Luna vs Kimi K3 FAQ

Which is cheaper, GPT-6 Luna or Kimi K3?

GPT-6 Luna is 97% cheaper per 1M input tokens than Kimi K3, $0.10 vs $3. For 10M input and 2M output tokens, GPT-6 Luna costs $2 and Kimi K3 $60 at standard rates.

Which is cheaper with prompt caching, GPT-6 Luna or Kimi K3?

GPT-6 Luna charges $0.01 per 1M cached input tokens, 90% below its standard input rate, and Kimi K3 $0.30, 90% below. With 9M of 10M input tokens cached and 2M output tokens, GPT-6 Luna costs $1.19 and Kimi K3 $35.70.

Which scores higher on independent benchmarks, GPT-6 Luna or Kimi K3?

Kimi K3 leads on Arena Text, 1488 Elo to 1443 Elo; Kimi K3 leads on GPQA Diamond, 93.1% to 90.5%; GPT-6 Luna leads on FrontierMath Tiers 1-3 (v2), 78.9% to 72.2%. Scores are independent evaluations, not either vendor's launch figures.

Which has the larger context window, GPT-6 Luna or Kimi K3?

Both accept about 1.05M tokens of context (1,050,000 and 1,048,576).

Can I run GPT-6 Luna or Kimi K3 myself?

Kimi K3 is released as open weights you can run yourself; GPT-6 Luna is available through its provider's API only.

Further reading

More on GPT-6 Luna and Kimi K3

Articles on GPT-6 Luna and Kimi K3

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Production evaluation

Choosing between GPT-6 Luna and Kimi K3?

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  • A head-to-head evaluation on your real workload
  • Routing between models by cost and difficulty
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