API cost decision in 10 seconds

KAT-Coder-Pro V2 vs GPT-5.1-Codex

Pick KAT-Coder-Pro V2 for lower cost; pick GPT-5.1-Codex 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-Pro V2 for lower cost; pick GPT-5.1-Codex only if the larger context window matters more.

On the standard 1M input plus 500K output workload, KAT-Coder-Pro V2 is estimated at $0.9 vs $6.25 for GPT-5.1-Codex, saving $5.35 (85.6% lower).

Cost-first pickKAT-Coder-Pro V2
Context-first pickGPT-5.1-Codex
Sample savings$5.3585.6%
10x traffic gap$53.5

GPT-5.1-Codex has more context, but KAT-Coder-Pro V2 saves $5.35 on the standard workload. At 10x that traffic, the same price gap is about $53.5. 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-Pro V2 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shapeToken mixBetter pickKAT-Coder-Pro V2GPT-5.1-Codex
Input-heavy / RAG5M input + 500K outputKAT-Coder-Pro V2$2.1$11.25
Balanced workload1M input + 1M outputKAT-Coder-Pro V2$1.5$11.25
Output-heavy chatbot1M input + 5M outputKAT-Coder-Pro V2$6.3$51.25
Cheaper input KAT-Coder-Pro V2 $0.3 vs $1.25 / 1M

KAT-Coder-Pro V2 is $0.95 cheaper per 1M input tokens (76% lower; 4.17x difference).

Cheaper output KAT-Coder-Pro V2 $1.2 vs $10 / 1M

KAT-Coder-Pro V2 is $8.8 cheaper per 1M output tokens (88% lower; 8.33x difference).

Larger context GPT-5.1-Codex 256K vs 400K

GPT-5.1-Codex has 144K more context (1.56x larger).

Sample workload KAT-Coder-Pro V2 $0.9 vs $6.25

KAT-Coder-Pro V2 is $5.35 cheaper on the standard workload (85.6% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
KAT-Coder-Pro V2 Calculating… Estimated API cost
GPT-5.1-Codex 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-Pro V2 has the lower input price; KAT-Coder-Pro V2 has the lower output price; GPT-5.1-Codex offers the larger context window. For the 1M input plus 500K output sample, KAT-Coder-Pro V2 is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $0.9 for KAT-Coder-Pro V2 and $6.25 for GPT-5.1-Codex.

Best Fit

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

Choose GPT-5.1-Codex when you care most about larger context window.

Decision Notes
  • On the standard 1M input plus 500K output workload, KAT-Coder-Pro V2 is estimated at $0.9 vs $6.25 for GPT-5.1-Codex, saving $5.35 (85.6% lower).
  • KAT-Coder-Pro V2 is $5.35 cheaper on the standard workload (85.6% lower).
  • KAT-Coder-Pro V2 is $0.95 cheaper per 1M input tokens (76% lower; 4.17x difference).
  • KAT-Coder-Pro V2 is $8.8 cheaper per 1M output tokens (88% lower; 8.33x difference).
  • GPT-5.1-Codex has 144K more context (1.56x larger).
Head-to-Head Specs
FeatureKAT-Coder-Pro V2
(Kwaipilot)		GPT-5.1-Codex
(OpenAI)
Input Price
prompt tokens per 1M		$0.3$1.25
Completion Price
per 1M tokens		$1.2$10
Sample Workload Cost
1M input + 500K output		$0.9$6.25
Context Window256K400K
Release Date

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productionKAT-Coder-Pro V2On the standard 1M input plus 500K output workload, KAT-Coder-Pro V2 is estimated at $0.9 vs $6.25 for GPT-5.1-Codex, saving $5.35 (85.6% lower).
High-volume input processingKAT-Coder-Pro V2Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsKAT-Coder-Pro V2Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document workGPT-5.1-CodexA 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-5.1-Codex when lower sample workload cost matters most: $0.
  • gpt-oss-20b (free) can replace GPT-5.1-Codex when lower sample workload cost matters most: $0.
  • gpt-oss-20b can replace GPT-5.1-Codex when lower sample workload cost matters most: $0.1.
  • gpt-oss-120b can replace GPT-5.1-Codex when lower sample workload cost matters most: $0.13.
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Cheaper alternatives

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Larger context alternatives

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Provider catalogs

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Kwaipilot catalog

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OpenAI catalog

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KAT-Coder-Pro V2

KAT-Coder-Pro V2 is the latest high-performance model in KwaiKAT’s KAT-Coder series, designed for complex enterprise-grade software engineering and SaaS integration. It builds on the agentic coding strengths of earlier versions,...

GPT-5.1-Codex

GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....