ANTHROPIC VS XAI
Claude Opus 5 vs Grok 4.5
Grok 4.5 is about 3.3x cheaper than Claude Opus 5 on a blended 3:1 input:output rate — the same 10K-in/2K-out request costs $0.032 vs $0.10. Claude Opus 5 has the larger context window (1,000,000 vs 500,000 tokens).
Pricing verified
API pricing per 1M tokens
| Model | Input / 1M tokens | Output / 1M tokens | Blended (3:1 mix) |
|---|---|---|---|
| Claude Opus 5 | $5.00 | $25.00 | $10.00 |
| Grok 4.5 | $2.00 | $6.00 | $3.00 |
Rates from official Anthropic pricing and official xAI pricing, checked 2026-08-11.
What a real workload costs
Example: one request with 10,000 input tokens and 2,000 output tokens, then that request at 100,000 runs per month.
| Model | Per request (10K in / 2K out) | Per month (100K requests) | Monthly delta |
|---|---|---|---|
| Claude Opus 5 | $0.10 | $10,000 | +$6,800 |
| Grok 4.5 | $0.032 | $3,200 | — |
Model your own prompt sizes and volumes in the token cost analyzer, or check caching savings with the prompt caching calculator.
Specs side by side
| Spec | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| Provider | Anthropic | xAI |
| Context window | 1,000,000 tokens | 500,000 tokens |
| Model class | Reasoning | Reasoning |
| Tokenizer | Proprietary (counts estimated) | Proprietary (counts estimated) |
Count tokens for each model on its own page: Claude Opus 5 token counter and Grok 4.5 token counter. All Anthropic models are on the Claude Token Counter. All xAI models are on the Grok Token Counter.
FAQ
Claude Opus 5 vs Grok 4.5 FAQ
Which is cheaper, Claude Opus 5 or Grok 4.5?
Grok 4.5 is cheaper. At rates checked 2026-08-11, Claude Opus 5 costs $5.00 input / $25.00 output per 1M tokens, while Grok 4.5 costs $2.00 input / $6.00 output — about a 3.3x difference on a typical 3:1 input-heavy workload.
How much does a real request cost on Claude Opus 5 vs Grok 4.5?
A request with 10,000 input tokens and 2,000 output tokens costs about $0.10 on Claude Opus 5 and $0.032 on Grok 4.5. At 100,000 such requests per month that is $10,000 vs $3,200 — a difference of $6,800 per month.
Which has the bigger context window, Claude Opus 5 or Grok 4.5?
Claude Opus 5. It supports 1,000,000 tokens of context versus 500,000 tokens — roughly 750,000 English words in one request.
Do Claude Opus 5 and Grok 4.5 count tokens the same way?
Not exactly. Claude Opus 5 uses a proprietary tokenizer (counts are estimates) and Grok 4.5 uses a proprietary tokenizer (counts are estimates). The same prompt will tokenize differently, which shifts effective cost per word.