Kimi K3 vs Claude Opus 4.8 — LLM API Cost Comparison
Compare Kimi K3 (Kimi (Moonshot AI)) vs Claude Opus 4.8 (Anthropic) on cost per million tokens, context window, and monthly spend.
Prices verified 2026-08-03 · Pricing may change — use the calculator for current estimates
- Input
- $3/1M tokens
- Output
- $15/1M tokens
- Context
- 1M tokens
- Released
- 2026-07
Kimi flagship; $0.30/1M cached input, 1M context, native multimodal and reasoning
- Input
- $5/1M tokens
- Output
- $25/1M tokens
- Context
- 1M tokens
- Released
- 2026-05
Latest Claude Opus; newest flagship from Anthropic
Monthly Cost by Usage Tier (70% input / 30% output ratio)
| Usage | Kimi K3 | Claude Opus 4.8 | Cheaper by |
|---|---|---|---|
| Light (1M tokens) | $6.60 | $11.00 | Kimi K3 (40%) |
| Moderate (10M tokens) | $66.00 | $110 | Kimi K3 (40%) |
| Heavy (100M tokens) | $660 | $1,100 | Kimi K3 (40%) |
| Very Heavy (1B tokens) | $6,600 | $11,000 | Kimi K3 (40%) |
Frequently Asked Questions
Which is cheaper — Kimi K3 or Claude Opus 4.8?
For input tokens, Kimi K3 is cheaper at $3/1M tokens — 1.7× less than $5/1M. For output tokens, Kimi K3 wins at $15/1M vs $25/1M. At heavy workloads (100M tokens/month), the cost difference can be significant.
What is the context window difference between Kimi K3 and Claude Opus 4.8?
Kimi K3 supports 1,048,576 tokens per request; Claude Opus 4.8 supports 1,000,000 tokens. Kimi K3 wins on context length, making it better for long documents, large codebases, or extended conversations without chunking.
When should I choose Kimi K3 over Claude Opus 4.8?
Choose Kimi K3 (Kimi (Moonshot AI)) if you prefer Kimi (Moonshot AI)'s ecosystem, tooling, or reliability track record. Kimi flagship; $0.30/1M cached input, 1M context, native multimodal and reasoning. Choose Claude Opus 4.8 (Anthropic) if Latest Claude Opus; newest flagship from Anthropic. the price/performance fits your workload better. Use this calculator to find the break-even point for your exact token volume.
How much does 1 billion tokens cost on Kimi K3 vs Claude Opus 4.8?
At 700M input + 300M output tokens (1B total): Kimi K3 costs $6600; Claude Opus 4.8 costs $11000. The difference is $4400/billion tokens at this 70/30 input/output ratio.