API cost decision in 10 seconds

Claude Opus 4.6 (Fast) vs Kimi K2.5

Pick Kimi K2.5 for lower cost; pick Claude Opus 4.6 (Fast) only if the larger context window matters more.

Pricing data updated:  Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Kimi K2.5 for lower cost; pick Claude Opus 4.6 (Fast) only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Kimi K2.5 is estimated at $1.35 vs $105 for Claude Opus 4.6 (Fast), saving $103.65 (98.7% lower).

Cost-first pickKimi K2.5
Context-first pickClaude Opus 4.6 (Fast)
Sample savings$103.6598.7%
10x traffic gap$1036.5

Claude Opus 4.6 (Fast) has more context, but Kimi K2.5 saves $103.65 on the standard workload. At 10x that traffic, the same price gap is about $1036.5. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Kimi K2.5 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shapeToken mixBetter pickClaude Opus 4.6 (Fast)Kimi K2.5
Input-heavy / RAG5M input + 500K outputKimi K2.5$225$2.95
Balanced workload1M input + 1M outputKimi K2.5$180$2.3
Output-heavy chatbot1M input + 5M outputKimi K2.5$780$9.9
Cheaper input Kimi K2.5 $30 vs $0.4 / 1M

Kimi K2.5 is $29.6 cheaper per 1M input tokens (98.7% lower; 75x difference).

Cheaper output Kimi K2.5 $150 vs $1.9 / 1M

Kimi K2.5 is $148.1 cheaper per 1M output tokens (98.7% lower; 78.9x difference).

Larger context Claude Opus 4.6 (Fast) 1M vs 262.14K

Claude Opus 4.6 (Fast) has 737.86K more context (3.81x larger).

Sample workload Kimi K2.5 $105 vs $1.35

Kimi K2.5 is $103.65 cheaper on the standard workload (98.7% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
Claude Opus 4.6 (Fast) Calculating… Estimated API cost
Kimi K2.5 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

Kimi K2.5 has the lower input price; Kimi K2.5 has the lower output price; Claude Opus 4.6 (Fast) offers the larger context window. For the 1M input plus 500K output sample, Kimi K2.5 is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $105 for Claude Opus 4.6 (Fast) and $1.35 for Kimi K2.5.

Best Fit

Choose Claude Opus 4.6 (Fast) when you care most about larger context window.

Choose Kimi K2.5 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, Kimi K2.5 is estimated at $1.35 vs $105 for Claude Opus 4.6 (Fast), saving $103.65 (98.7% lower).
  • Kimi K2.5 is $103.65 cheaper on the standard workload (98.7% lower).
  • Kimi K2.5 is $29.6 cheaper per 1M input tokens (98.7% lower; 75x difference).
  • Kimi K2.5 is $148.1 cheaper per 1M output tokens (98.7% lower; 78.9x difference).
  • Claude Opus 4.6 (Fast) has 737.86K more context (3.81x larger).
Head-to-Head Specs
FeatureClaude Opus 4.6 (Fast)
(Anthropic)		Kimi K2.5
(MoonshotAI)
Input Price
prompt tokens per 1M		$30$0.4
Completion Price
per 1M tokens		$150$1.9
Sample Workload Cost
1M input + 500K output		$105$1.35
Context Window1M262.14K
Release Date

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productionKimi K2.5On the standard 1M input plus 500K output workload, Kimi K2.5 is estimated at $1.35 vs $105 for Claude Opus 4.6 (Fast), saving $103.65 (98.7% lower).
High-volume input processingKimi K2.5Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsKimi K2.5Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document workClaude Opus 4.6 (Fast)A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps
  • Claude 3 Haiku can replace Claude Opus 4.6 (Fast) when lower sample workload cost matters most: $0.88.
  • Claude 3.5 Haiku can replace Claude Opus 4.6 (Fast) when lower sample workload cost matters most: $2.8.
  • Anthropic Claude Haiku Latest can replace Claude Opus 4.6 (Fast) when lower sample workload cost matters most: $3.5.
  • Claude Haiku 4.5 can replace Claude Opus 4.6 (Fast) when lower sample workload cost matters most: $3.5.
Popular competitors
  • No popular competitor is currently available.

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

Compare models within provider hubs before choosing a final API vendor.

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Anthropic catalog

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

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MoonshotAI catalog

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

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Claude Opus 4.6 (Fast)

Fast-mode variant of [Opus 4.6](/anthropic/claude-opus-4.6) - identical capabilities with higher output speed at premium 6x pricing. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-mode

Kimi K2.5

Kimi K2.5 is Moonshot AI's native multimodal model, delivering state-of-the-art visual coding capability and a self-directed agent swarm paradigm. Built on Kimi K2 with continued pretraining over approximately 15T mixed...