Comparison
FastMetal vs OpenRouter
FastMetal and OpenRouter are both gateways that put many providers' models behind one API key. Both are OpenAI-compatible and both bill per token.
The real difference is who each is built for. OpenRouter is a global, USD-billed service. FastMetal is built for teams in Japan, with JPY billing and Japanese-language support as the starting point — and US-dollar accounts for anyone who budgets in dollars.
At a glance
| Aspect | FastMetal | OpenRouter |
|---|---|---|
| Billing and invoices | Prepaid in JPY or USD, chosen per account. No subscription. Card, or Japanese bank transfer for JPY; qualified invoices on JPY purchases | Prepaid credits in USD |
| API compatibility | OpenAI-compatible, plus an Anthropic-compatible /v1/messages endpoint | OpenAI-compatible endpoint |
| Models and providers | 90+ models, including Japanese domestic models | A larger catalog |
| Automatic routing | Set the model to auto and it picks the cheapest model that covers what the request needs, falling back to the next candidate on failure | Auto Router, provider-level routing, and fallbacks |
| Modalities | Text, image, and video generation and structured decisions. Also reachable over MCP | Text plus images and more, varying by provider |
| Operational burden | Managed. Nothing to operate | Managed. Nothing to operate |
| Language and support | Japanese UI, docs, and support | Primarily English |
| Data flow | Requests are relayed to each model's provider | Requests are relayed to each model's provider |
When OpenRouter fits
- You want the largest possible model catalog. OpenRouter carries more models and tends to add new ones quickly.
- USD billing is no problem for you, and English docs and community are all you need.
- You want fine-grained routing control, such as automatic provider routing and fallbacks.
When FastMetal fits
- You want billing in JPY, with no exchange-rate mental math or foreign card fees, and expenses that drop straight into Japanese accounting.
- You need Japanese qualified invoices. FastMetal is a registered qualified invoice issuer.
- You want a Japanese UI, docs, and support, plus Japanese-focused domestic models on the same API.
OpenRouter changes over time. This is a broad-strokes comparison based on public information; check each service's current docs for specific features.
This comparison reflects public information as of September 2026.
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