Comparison · prices as of 2026-07-04 · re-verified 2026-08-18
Claude Opus 4.5 vs Grok 4
On price alone, Grok 4 (xAI) runs about 40% cheaper than Claude Opus 4.5 for a typical chat workload (2K input + 500 output tokens, 1,000 requests/day). Whether that's the right trade depends on the capability gap — the breakdown below shows where each one wins.
Price per million tokens
| Spec | Claude Opus 4.5 | Grok 4 |
|---|---|---|
| Input / MTok | $5 | $3 |
| Output / MTok | $25 | $15 |
| Context window | 200K | 256K |
| Max output | 64K | 64K |
| Class | frontier | frontier |
Estimated monthly cost by workload
Same models, three realistic usage levels. The gap between them scales with volume, so the right pick can change as you grow.
| Workload | Claude Opus 4.5 | Grok 4 | Cheaper |
|---|---|---|---|
| Light — chatbot 0.5K in / 0.2K out · 200 req/day | $45.00 | $27.00 | Grok 4 |
| Typical — assistant 2K in / 0.5K out · 1K req/day | $675 | $405 | Grok 4 |
| Heavy — RAG / agent 8K in / 2K out · 5K req/day | $13,500 | $8,100 | Grok 4 |
Which should you pick?
- Cheapest overall: Grok 4 — about 40% less per month on a typical assistant workload.
- Grok 4 is cheaper on both input and output, so it stays cheaper whether your workload is prompt-heavy or generation-heavy.
- Largest context window: Grok 4 at 256K tokens vs 200K — the one to pick if you feed in whole documents or codebases.
Frequently asked questions
Is Claude Opus 4.5 or Grok 4 cheaper?
Grok 4 is cheaper — roughly 40% less per month on a typical assistant workload (2K input + 500 output tokens, 1,000 requests/day).
What do Claude Opus 4.5 and Grok 4 cost per million tokens?
Claude Opus 4.5 is $5 per million input tokens and $25 per million output. Grok 4 is $3 input and $15 output. Prices are first-party API list rates as of 2026-07-04.
Which has the larger context window, Claude Opus 4.5 or Grok 4?
Grok 4 does, at 256K tokens versus 200K for Claude Opus 4.5.
When should I choose Claude Opus 4.5 over Grok 4?
Both are frontier-class models, so choose Claude Opus 4.5 when it measurably wins on your own evals or you prefer its provider (Anthropic); otherwise Grok 4 does the same job for less.
Related comparisons
Sources: Anthropic pricing · xAI pricing. Run your own numbers in the cost calculator.