AI model comparison
Kimi K3.1 Pro vs Claude Sonnet 5.5
Side by side comparison of Kimi K3.1 Pro and Claude Sonnet 5.5 on pricing, benchmark scores, context window, and more.
Kimi K3.1 Pro is Moonshot AI's flagship open-weight multimodal reasoning model and a post-trained successor to Kimi K3, with a 1M-token context window.
- Input / 1M
- $2
- Output / 1M
- $10
- Context
- 1.05M
Claude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade.
- Input / 1M
- $2
- Output / 1M
- $10
- Context
- 1M
Comparing image generators? Compare image models
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
Tie
Same price for a typical chat
Higher intelligence score
Claude Sonnet 5.5
56 vs 55.1 on Artificial Analysis
Larger context window
Kimi K3.1 Pro
1.05M vs 1M tokens
Newer release
Kimi K3.1 Pro
Released October 23, 2026
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
Claude Sonnet 5.556Coding index
Claude Sonnet 5.5Not availableAgentic index
Claude Sonnet 5.5Not availablePricing
Kimi K3.1 Pro vs Claude Sonnet 5.5 API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | Claude Sonnet 5.5 | |
|---|---|---|
| Input tokensPer 1M tokens | $2 | $2 |
| Output tokensPer 1M tokens | $10 | $10 |
| Cached input (read)Per 1M tokens | $0.20 | $0.10 |
| Cache writePer 1M tokens | Not available | $2.50 |
| Web searchPer request | Not available | $0.01 |
What it costs in practice
Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.
Chat message
2K in, 500 out
Claude Sonnet 5.5$9Coding task
30K in, 4K out
Claude Sonnet 5.5$100$43 cachedLong document summary
150K in, 2K out
Claude Sonnet 5.5$320$35 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | Claude Sonnet 5.5 | |
|---|---|---|
| Context window | 1.05M tokens | 1M tokens |
| Max output | 944K tokens | 128K tokens |
| Input types | Image, Text, Video | File, Image, Text |
| Output types | Text | Text |
| Reasoning effort levels | Max, High, Low, None | Max, Extra high, High, Medium, Low |
| Default reasoning effort | Max | High |
| Release date | October 23, 2026 | September 28, 2026 |
Features
Supported features
API features available for each model.
| Metric | Claude Sonnet 5.5 | |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Not supported | Not supported |
| Stop sequences | Supported | Supported |
| Deterministic seed | Not supported | Not supported |
| Verbosity control | Not supported | Supported |
Keep exploring
More on these models
Other head-to-heads, the full model page, and the alternatives list for each model.
- Kimi K3.1 Pro vs Claude Opus 5.5
- Kimi K3.1 Pro vs Claude Fable 5.1
- Kimi K3.1 Pro vs GPT-6 Astra
- Kimi K3.1 Pro vs Gemini 4 Argon
- Kimi K3.1 Pro vs GPT-6.1 Sol
- Kimi K3.1 Pro vs Claude Opus 5
- Kimi K3.1 Pro vs Claude Fable 5
- Kimi K3.1 Pro vs Muse Spark 1.3
- Kimi K3.1 Pro vs GPT-6 Sol
- Kimi K3.1 Pro vs Grok 4.7
- Kimi K3.1 Pro vs Kimi K3
- Kimi K3.1 Pro vs GLM 5.3 Flash
- Kimi K3.1 Pro vs DeepSeek V4.1 Flash 1017
- Kimi K3.1 Pro vs MiMo-V2.6-Flash
- Kimi K3.1 Pro vs DeepSeek V4.1 Flash
- Kimi K3.1 Pro vs Hy4 preview
Claude Sonnet 5.5View full model details- Claude Sonnet 5.5 vs Claude Opus 5.5
- Claude Sonnet 5.5 vs Claude Fable 5.1
- Claude Sonnet 5.5 vs GPT-6 Astra
- Claude Sonnet 5.5 vs Gemini 4 Argon
- Claude Sonnet 5.5 vs GPT-6.1 Sol
- Claude Sonnet 5.5 vs Claude Opus 5
- Claude Sonnet 5.5 vs Claude Fable 5
- Claude Sonnet 5.5 vs Muse Spark 1.3
- Claude Sonnet 5.5 vs GPT-6 Sol
- Claude Sonnet 5.5 vs DeepSeek V4.1 Flash 1017
- Claude Sonnet 5.5 vs DeepSeek V4.1 Flash
- Claude Sonnet 5.5 vs GLM 5.3 Flash
- Claude Sonnet 5.5 vs Hy4 preview
- Claude Sonnet 5.5 vs Kimi K3
- Claude Sonnet 5.5 vs MiMo-V2.6-Flash
- Claude Sonnet 5.5 vs Muse Wonder
Our take
Claude Sonnet 5.5 scores higher on the Artificial Analysis Intelligence Index (56 vs 55.1). Kimi K3.1 Pro has the larger context window (1.05M vs 1M tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.
FAQ
Frequently asked questions
Is Kimi K3.1 Pro or Claude Sonnet 5.5 cheaper?
Kimi K3.1 Pro and Claude Sonnet 5.5 cost the same for a typical chat (2K input tokens and 500 output tokens). Kimi K3.1 Pro costs $2 per 1M input tokens and $10 per 1M output tokens, and Claude Sonnet 5.5 costs $2 per 1M input tokens and $10 per 1M output tokens.
Which has a bigger context window, Kimi K3.1 Pro or Claude Sonnet 5.5?
Kimi K3.1 Pro supports up to 1.05M tokens of context, compared with 1M for Claude Sonnet 5.5.
Is Kimi K3.1 Pro smarter than Claude Sonnet 5.5?
On the Artificial Analysis Intelligence Index, Kimi K3.1 Pro scores 55.1 and Claude Sonnet 5.5 scores 56, putting Claude Sonnet 5.5 ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.
Can I use Kimi K3.1 Pro and Claude Sonnet 5.5 at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Kimi K3.1 Pro and Claude Sonnet 5.5 answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to Kimi K3.1 Pro and Claude Sonnet 5.5 at the same time. Compare the answers side by side and keep the best one.