Claude Opus 4.8 vs Grok 4.1 Fast
A direct API-pricing comparison between Claude Opus 4.8 and Grok 4.1 Fast. Below: every cost dimension side by side, then the bottom line for a typical workload.
Bottom line
For a typical 5K-in / 1K-out request, Grok 4.1 Fast is the cheaper choice at $0.0015 per call — 33.3× less than Claude Opus 4.8 at $0.050.
| Claude Opus 4.8Anthropic | Grok 4.1 FastxAI | |
|---|---|---|
| Input / 1M tokens | $5.00 | $0.200 |
| Output / 1M tokens | $25.00 | $0.500 |
| Cached input / 1M | $0.500 | — |
| Context window | 200K | 256K |
| Provider | Anthropic | xAI |
Green = cheaper on that line. Prices are estimates from public pricing pages; verify against Anthropic and xAI before relying on them.
Which is cheaper, Claude Opus 4.8 or Grok 4.1 Fast?
On output tokens — usually the dominant cost — Claude Opus 4.8 charges $25.00 per million versus $0.500 for Grok 4.1 Fast. The right pick depends on your input/output ratio and how much you can serve from cache. Use the calculator to model your exact traffic.