Claude Opus 4vsMercury
Mercury is cheaper than Claude Opus 4 at $10/M vs $15/M input tokens.
| Spec | Claude Opus 4 | Mercury |
|---|---|---|
| Input price | $15/M tokens | $10/M tokens |
| Output price | $75/M tokens | $10/M tokens |
| Context window | 200K tokens | 32K tokens |
| Parameters | Not disclosed | Not disclosed |
| Weights | Closed | — |
| Free API (OpenRouter) | No | No |
| Released | May 2025 | Jun 2025 |
Our Verdict
Claude Opus 4
MercuryRunner-up
Not enough votes to call it. On the specs, Claude Opus 4 has the edge: bigger model tier, bigger context window, major provider backing.
Mercury costs 7.5x less per token.
Too close to call
API pricing
Cost per 1M tokens
Claude Opus 4
Input
$15.00
Output
$75.00
Mercury
Input
$10.00
1.5× cheaper
Output
$10.00
7.5× cheaper
Mercury is cheaper on both: 1.5× input, 7.5× output.
Where to run it
1 host
Claude Opus 41 host
Mercury
No hosts listed on OpenRouter.
Per million tokens. Prices and uptime via OpenRouter, checked 9 Sep 2026.
Writing DNA
Style Comparison
Similarity
40%
Claude Opus 4 uses 42.6x more emoji
Claude Opus 4
Mercury
65%Vocabulary60%
57wSentence Length31w
0.67Hedging0.78
3.8Bold4.1
6.8Lists2.8
1.18Emoji0.03
1.42Headings0.88
0.22Transitions0.06
Based on 27 + 26 text responses
Research
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