Claude Sonnet 4.5 vs Kimi K2.5
Complete pricing and performance comparison between Anthropic's Claude Sonnet 4.5 and Moonshot's Kimi K2.5.
Quick Verdict
Cheaper
Kimi K2.5
5.0x cheaper input, 5.0x cheaper output
Larger Context
Claude Sonnet 4.5
200K vs 128K
Pricing Comparison
| Spec | Claude Sonnet 4.5 | Kimi K2.5 | Difference |
|---|---|---|---|
| Provider | Anthropic | Moonshot | |
| Input / 1M tokens | $3 | $0.6 | Kimi K2.5 is 80% more expensive |
| Output / 1M tokens | $15 | $3 | Kimi K2.5 is 80% more expensive |
| Context Window | 200K | 128K | 2x difference |
| Max Output | 64K | 33K |
Performance Benchmarks
| Metric | Claude Sonnet 4.5 | Kimi K2.5 | Winner |
|---|---|---|---|
| Quality Index | -- | 47 | N/A |
| Output Speed | -- | 46 tok/s | N/A |
| Value (Quality/$) | -- | 78.0 | Higher = better value |
Benchmark data from Artificial Analysis. Quality Index is a composite score across reasoning, coding, and knowledge tasks.
Cost at Scale
Estimated cost at different usage levels (3:1 input-to-output token ratio, typical for chat).
| Usage | Claude Sonnet 4.5 | Kimi K2.5 | Savings |
|---|---|---|---|
Single request 1K in / 300 out | $0.0075 | $0.0015 | Kimi K2.5 saves $0.0060 |
10 requests 10K in / 3K out | $0.075 | $0.015 | Kimi K2.5 saves $0.060 |
100 requests 100K in / 30K out | $0.750 | $0.150 | Kimi K2.5 saves $0.600 |
1,000 requests 1M in / 300K out | $7.50 | $1.50 | Kimi K2.5 saves $6.00 |
10,000 requests 10M in / 3M out | $75.00 | $15.00 | Kimi K2.5 saves $60.00 |
1M requests/mo 1B in / 300M out | $7500.00 | $1500.00 | Kimi K2.5 saves $6000.00 |
Pros & Cons
Claude Sonnet 4.5 Strengths
- +Larger context window (200K vs 128K)
- +Higher max output tokens
Kimi K2.5 Strengths
- +Cheaper input tokens
- +Cheaper output tokens
When to Use Each Model
Choose Claude Sonnet 4.5 for
- →Long documents, large codebases, or multi-turn conversations
- →Generating long-form content or detailed code
Choose Kimi K2.5 for
- →Budget-conscious projects where cost is the primary factor
Frequently Asked Questions
Which is cheaper, Claude Sonnet 4.5 or Kimi K2.5?
For input tokens, Kimi K2.5 is 5.0x cheaper at $0.6/1M tokens. For output tokens, Kimi K2.5 is 5.0x cheaper at $3/1M tokens. At typical usage (1M input + 300K output), Claude Sonnet 4.5 costs $7.50 vs Kimi K2.5 at $1.50.
What's the context window difference?
Claude Sonnet 4.5 supports 200K context (200,000 tokens), while Kimi K2.5 supports 128K (128,000 tokens). Claude Sonnet 4.5 can handle 2x more context in a single request.
Which model has better benchmarks?
When should I choose Claude Sonnet 4.5 over Kimi K2.5?
Choose Claude Sonnet 4.5 when you need: Larger context window (200K vs 128K), Higher max output tokens. Choose Kimi K2.5 when you need: Cheaper input tokens, Cheaper output tokens.
How much would 10,000 API requests cost?
At 1K input + 300 output tokens per request (typical chat): Claude Sonnet 4.5 = $75.00, Kimi K2.5 = $15.00. At 10K input + 1K output per request (longer conversations): Claude Sonnet 4.5 = $450.00, Kimi K2.5 = $90.00.