Kimi K3 vs Claude Opus 4.8 compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.
Claude Opus 4.8 — full profile ›
Prices & specs refreshed from live data · OpenSourceAI.tech
Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.
| Spec | Kimi K3 | Claude Opus 4.8 |
|---|---|---|
| Maker | Moonshot AI | Anthropic |
| Type | Open-weight | Proprietary |
| Context window | 1M tokens | 1M tokens |
| Input price | $3/M · free self-host | $5/M |
| Output price | $15/M · free self-host | $25/M |
| Vision / multimodal | Yes | Yes |
| Tool / function calling | Yes | Yes |
| Self-hostable | Yes | No (API only) |
| License | Modified MIT | Proprietary |
| Capability | Kimi K3 | Claude Opus 4.8 |
|---|---|---|
| Open weights (downloadable) | ✓ | ✗ |
| Self-hostable | ✓ | ✗ |
| Runs fully offline | ✓ | ✗ |
| Vision / multimodal | ✓ | ✓ |
| Tool / function calling | ✓ | ✓ |
| 1M+ context window | ✓ | ✓ |
Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).
Benchmark data by Artificial Analysis.
| Criterion | Kimi K3 | Claude Opus 4.8 |
|---|---|---|
| Cost-efficiency | 3.0 | 3.0 |
| Context window | 5.0 | 5.0 |
| Openness | 5.0 | 1.5 |
| Self-hosting | 5.0 | 1.0 |
| Multimodality | 5.0 | 5.0 |
Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.
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...
Claude Opus 4.8 is Anthropic's most capable generally available model in the Opus family. It supports text, image, and file inputs with text output, with reasoning support and a 1M-token...
These variants are tracked but not compared here — one page per family keeps the comparison readable.
Kimi K3 is open-weight and competitive on many tasks, but Claude Opus 4.8 may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.
Yes. Kimi K3 has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. Claude Opus 4.8 is API-only and cannot be self-hosted.
Kimi K3 costs $15/M output vs $25/M for Claude Opus 4.8 — roughly 2x cheaper via API, and free if you self-host.
Choose Kimi K3 if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose Claude Opus 4.8 if you want frontier capability through a managed API with zero infrastructure to run.
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