Claude Sonnet 5 vs Kimi K3: Specs & Benchmark Comparison
Claude Sonnet 5 is developed by Anthropic, while Kimi K3 comes from Moonshot AI. Claude Sonnet 5 was released in June 2026, and Kimi K3 followed a month later in July 2026. Kimi K3 has a published size of about 2.8 trillion parameters; Anthropic has not disclosed the parameter count of Claude Sonnet 5.
The two models share 7 published benchmarks. Kimi K3 leads on 6 of them, Claude Sonnet 5 on 1. The widest gaps are on Toolathlon, where Kimi K3 scores 73.2% against 54.3%; AutomationBench, where Kimi K3 scores 30.8% against 13.5%. Averaged across everything we track, Claude Sonnet 5 sits at 58.4% and Kimi K3 at 67.8%.
Claude Sonnet 5 is the cheaper API at $2 per million input tokens and $10 per million output tokens, about 50% below Kimi K3 at $3 and $15. Both accept a context window of about 1M tokens. Both accept text and images as input.
| Characteristic | Claude Sonnet 5 | Kimi K3 |
|---|---|---|
| Company | Anthropic | Moonshot AI |
| Release Date | June 30, 2026 | July 16, 2026 |
| Parameters | — | 2.8T |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 1.0M |
| Context (output) | 64K | 1.0M |
| Input Price / 1M | $2.00 | $3.00 |
| Output Price / 1M | $10.00 | $15.00 |
| Average Score | 58.4% | 67.8% |
| Benchmarks | ||
| Toolathlon | 54.3% | 73.2% |
| AutomationBench | 13.5% | 30.8% |
| DeepSWE 1.1 | 54.0% | 69.0% |
| BrowseComp | 84.7% | 91.2% |
| OfficeQA Pro | 59.4% | 63.3% |
| CharXiv-R | 88.3% | 91.3% |
| Humanity's Last Exam | 57.4% | 56.0% |
Visual Benchmark Comparison
Verdict
Both models show equal results — the choice depends on your specific use case.
Both models show comparable average scores: Claude Sonnet 5 — 0.6, Kimi K3 — 0.7.
Claude Sonnet 5 is 1.5x cheaper: input $2.00/1M vs $3.00/1M tokens.
Same context size: 1M tokens.
Kimi K3 is newer: released 7/16/2026 vs 6/30/2026.
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Frequently Asked Questions
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The Claude Sonnet 5 and Kimi K3 comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Claude Sonnet 5 or Kimi K3 page. See also the complete list of AI model comparisons.