Claude Opus 5 (Fast) vs Kimi K3
Detailed technical comparison between Claude Opus 5 (Fast) (Anthropic) and Kimi K3 (Moonshot AI). Review live API token pricing, context window capabilities, time-to-first-token latency, and verified benchmark scores side-by-side.
Comparison Snapshot
Kimi K3
1,048,576 tokensTie
Equal CapabilityTie
Equal SpeedKimi K3
$3.00 / MTokClaude Opus 5 (Fast)
Fast-mode variant of [Opus 5](/anthropic/claude-opus-5) - identical capabilities with higher output speed at 2x pricing relative to regular Opus 5. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-mode
Kimi K3
Kimi K3 is a 2.8T parameter open-weight multimodal reasoning model from Moonshot AI. It is suited for complex coding, knowledge work, and long-horizon agentic workflows, and is particularly strong at...
Technical Specifications
🏆 = Superior Spec| Specification | Claude Opus 5 (Fast) | Kimi K3 |
|---|---|---|
| Provider | Anthropic | Moonshot AI |
| Context Window | 1,000,000 tokens | 1,048,576 tokens🏆 |
| Agent Suitability | Not yet benchmarked | Not yet benchmarked |
| Time to First Token (TTFT) | No public TTFT data | No public TTFT data |
| Deployment Model | managed api | managed api |
| Production Stability | Beta Access (est.) | Beta Access (est.) |
| API Available | Yes | Yes |
| Released Date | 2026-07-24 | 2026-07-16 |
API Pricing Comparison
Input Price per Million Tokens
Claude Opus 5 (Fast)
$10.00
Kimi K3
$3.00
Output Price per Million Tokens
Claude Opus 5 (Fast)
$50.00
Kimi K3
$15.00
💡 Cost Ratio: Kimi K3 is 3.3x cheaper per input token than Claude Opus 5 (Fast).
Want to test both models live?
Run side-by-side prompt benchmarks in our dynamic multi-model Sandbox. Compare execution speeds, latency metrics, and compute actual costs in real-time.
Benchmark Performance Metrics
Standardized Scores (0–100%)Scores show verified raw accuracy percentages across standardized AI evaluation suites. Higher bars indicate superior performance in that domain.
Claude Opus 5 (Fast) Quirks & Gotchas
No developer gotchas reported.
Kimi K3 Quirks & Gotchas
No developer gotchas reported.
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