API cost decision in 10 seconds

🔥GPT-5.6 Luna vs KAT-Coder-Air V2.5

Pick KAT-Coder-Air V2.5 for lower cost; pick GPT-5.6 Luna only if the larger context window matters more.

Page updated:  Data confirmed:  Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick KAT-Coder-Air V2.5 for lower cost; pick GPT-5.6 Luna only if the larger context window matters more.

On the standard 1M input plus 500K output workload, KAT-Coder-Air V2.5 is estimated at $0.45 vs $0.8 for GPT-5.6 Luna, saving $0.35 (43.8% lower).

Cost-first pickKAT-Coder-Air V2.5
Context-first pickGPT-5.6 Luna
Sample savings$0.3543.8%
10x traffic gap$3.5

GPT-5.6 Luna has more context, but KAT-Coder-Air V2.5 saves $0.35 on the standard workload. At 10x that traffic, the same price gap is about $3.5. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

KAT-Coder-Air V2.5 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shapeToken mixBetter pickGPT-5.6 LunaKAT-Coder-Air V2.5
Input-heavy / RAG5M input + 500K outputKAT-Coder-Air V2.5$1.6$1.05
Balanced workload1M input + 1M outputKAT-Coder-Air V2.5$1.4$0.75
Output-heavy chatbot1M input + 5M outputKAT-Coder-Air V2.5$6.2$3.15
Cheaper input KAT-Coder-Air V2.5 $0.2 vs $0.15 / 1M

KAT-Coder-Air V2.5 is $0.05 cheaper per 1M input tokens (25% lower; 1.33x difference).

Cheaper output KAT-Coder-Air V2.5 $1.2 vs $0.6 / 1M

KAT-Coder-Air V2.5 is $0.6 cheaper per 1M output tokens (50% lower; 2x difference).

Larger context GPT-5.6 Luna 1.05M vs 256K

GPT-5.6 Luna has 794K more context (4.1x larger).

Sample workload KAT-Coder-Air V2.5 $0.8 vs $0.45

KAT-Coder-Air V2.5 is $0.35 cheaper on the standard workload (43.8% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
GPT-5.6 Luna Calculating… Estimated API cost
KAT-Coder-Air V2.5 Calculating… Estimated API cost
Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

KAT-Coder-Air V2.5 has the lower input price; KAT-Coder-Air V2.5 has the lower output price; GPT-5.6 Luna offers the larger context window. For the 1M input plus 500K output sample, KAT-Coder-Air V2.5 is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $0.8 for GPT-5.6 Luna and $0.45 for KAT-Coder-Air V2.5.

Best Fit

Choose GPT-5.6 Luna when you care most about larger context window.

Choose KAT-Coder-Air V2.5 when you care most about lower input-token price, and lower output-token price.

Decision Notes
  • On the standard 1M input plus 500K output workload, KAT-Coder-Air V2.5 is estimated at $0.45 vs $0.8 for GPT-5.6 Luna, saving $0.35 (43.8% lower).
  • KAT-Coder-Air V2.5 is $0.35 cheaper on the standard workload (43.8% lower).
  • KAT-Coder-Air V2.5 is $0.05 cheaper per 1M input tokens (25% lower; 1.33x difference).
  • KAT-Coder-Air V2.5 is $0.6 cheaper per 1M output tokens (50% lower; 2x difference).
  • GPT-5.6 Luna has 794K more context (4.1x larger).
Head-to-Head Specs
Feature🔥GPT-5.6 Luna
(OpenAI)		KAT-Coder-Air V2.5
(Kwaipilot)
Input Price
prompt tokens per 1M		$0.2$0.15
Completion Price
per 1M tokens		$1.2$0.6
Sample Workload Cost
1M input + 500K output		$0.8$0.45
Context Window1.05M256K
Release Date
Popularity#6

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productionKAT-Coder-Air V2.5On the standard 1M input plus 500K output workload, KAT-Coder-Air V2.5 is estimated at $0.45 vs $0.8 for GPT-5.6 Luna, saving $0.35 (43.8% lower).
High-volume input processingKAT-Coder-Air V2.5Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsKAT-Coder-Air V2.5Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document workGPT-5.6 LunaA larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps
  • gpt-oss-120b (free) can replace GPT-5.6 Luna when lower sample workload cost matters most: $0.
  • gpt-oss-20b (free) can replace GPT-5.6 Luna when lower sample workload cost matters most: $0.
  • gpt-oss-20b can replace GPT-5.6 Luna when lower sample workload cost matters most: $0.1.
  • gpt-oss-120b can replace GPT-5.6 Luna when lower sample workload cost matters most: $0.12.

Cheaper alternatives

Review low-cost models sorted by a standard 1M input plus 500K output workload.

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Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

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Provider catalogs

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OpenAI catalog

Review all tracked OpenAI models before deciding whether this matchup is the right shortlist.

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Kwaipilot catalog

Check other Kwaipilot models with comparable pricing, context, or release timing.

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GPT-5.6 Luna

GPT-5.6 Luna is a fast, cost-efficient model in OpenAI's GPT-5.6 series. It is suited for high-volume, latency-sensitive tasks such as chat, classification, and lightweight agentic workflows, providing capable reasoning for...

KAT-Coder-Air V2.5

KAT-Coder-Air V2.5 is a flagship-level Agentic Coding model that can directly hand over an entire issue or an entire business workflow to it, allowing it to autonomously locate and make...