Comparison · Anthropic and MoonshotAI
Claude Sonnet 5.5 vs Kimi K3
Listed API prices of Claude Sonnet 5.5 and Kimi K3 turned into the cost of the same three standard tasks, with speed from our own test requests in the United States. Output quality and answer length are not compared.
Calculated impact cost per task and per month
For an L2 task (deep analysis over a 50,000-token document, 3 steps), Claude Sonnet 5.5 costs $0.348 and Kimi K3 $0.522 at the prices listed in the United States on , so Claude Sonnet 5.5 is 33.3 % less than Kimi K3, counting visible output only, without cache discounts or hidden reasoning.
| Task | Claude Sonnet 5.5, per task | Kimi K3, per task | Claude Sonnet 5.5, per month | Kimi K3, per month | Claude Sonnet 5.5 vs Kimi K3, per task |
|---|---|---|---|---|---|
| L1Micro-task (classification or strict JSON extraction) | $0.0050per L1 task | $0.0075per L1 task | $73.00per month | $109.50per month | −33.3 % |
| L2Deep analysis over a 50,000-token document | $0.348per L2 task | $0.522per L2 task | $5,080.80per month | $7,621.20per month | −33.3 % |
| L3Agentic coding loop, 15 steps | $2.72per L3 task | $4.08per L3 task | $39,726.60per month | $59,589.90per month | −33.3 % |
Calculated Per month: 20 tasks an hour around the clock, 730 hours.
Prices USD per 1M tokens
| Price | Claude Sonnet 5.5 | Kimi K3 |
|---|---|---|
| Input, per 1M tokens | $2.00 | $3.00 |
| Output, per 1M tokens | $10.00 | $15.00 |
| Price from | Provider's price list · source page Published | Provider's price list · source page Published |
| Read | · the United States | · the United States |
| Context window | 1,000,000 tokens | 1,048,576 tokens |
What can I use it for? six common tasks, our data checks
Quality on your task: not measured by Measured Lab yet.
| Task | Claude Sonnet 5.5 | Kimi K3 |
|---|---|---|
| Answer customer messages | Fits on price and context | Fits on price and context |
| Pull data from invoices and documents with strict JSON and page images | Fits on price and context | Not confirmed: strict JSON output not in our data |
| Summarize documents and meetings | Fits on price and context | Fits on price and context |
| Translate content | Fits on price and context | Fits on price and context |
| Chat assistant on your website | Fits on price and context | Fits on price and context |
| Write and review code with tool calls | Fits on price and context | Not confirmed: tool calls not in our data |
| Tasks it fits | 6 of 6 | 4 of 6 |
Checks of our data for six common tasks: a published price, a context window and answer length for the task and, where the task needs them, strict JSON output, page images and tool calls; prices, cost a month and terms for each model on its model card. Compare models for your own task in the model picker.
Speed in the US Observed our test requests
In our test requests from the United States, the median time to the first answer token was 961 ms for Claude Sonnet 5.5 (Direct API · Anthropic) and 10,892 ms for Kimi K3 (Direct API · Moonshot AI).
| Model and route | Time to first answer token, median | Output speed, median | Answers |
|---|---|---|---|
| Claude Sonnet 5.5Direct API · Anthropic | 961 ms range 363 ms–8,537 ms | 115 tokens/s range 67.7 tokens/s–244 tokens/s | 115 answers on 23 dates |
| Kimi K3Direct API · Moonshot AI | 10,892 ms range 4,580 ms–22,396 ms | 75.1 tokens/s range 43.6 tokens/s–260 tokens/s | 115 answers on 23 dates |
| Kimi K3OpenRouter → Moonshot AI | 10,666 ms range 5,455 ms–48,174 ms | 61.5 tokens/s range 42.4 tokens/s–146 tokens/s | 75 answers on 15 dates |
The same short request to every model, sent from a measurement point in the United States; medians of successful answers on at least 2 different dates, latest on . How we measure
Price changes in the last 30 days
- The listed price of Kimi K3 changed on on OpenRouter: output $12.53 → $11.94 per 1M tokens.
- The listed price of Kimi K3 changed on on OpenRouter: input $0.30 → $0.24 per 1M tokens.
- The listed price of Kimi K3 changed on on OpenRouter: output $11.94 → $10.80 per 1M tokens.
- The listed price of Kimi K3 changed on on OpenRouter: input $0.24 → $0.19 per 1M tokens.
- The listed price of Kimi K3 changed on on OpenRouter: output $10.80 → $15.00 per 1M tokens.
- The listed price of Kimi K3 changed on on OpenRouter: output $15.00 → $16.00 per 1M tokens.