Claude Opus 5.5 vs 
Quasar Alpha
Claude Opus 5.5 is the newer model, released after Quasar Alpha.
Minimalist Landing Page
Whole landing page for a startup that reads your face. It renders or it doesn't.
Loading the build
Loading the build
Which answer wins?
Price and specs
Not enough votes to call it. On the specs, Claude Opus 5.5 has the edge: newer, major provider backing.
| Spec | Claude Opus 5.5 | Quasar Alpha |
|---|---|---|
| Input price | $4/M tokens | — |
| Output price | $20/M tokens | — |
| Context window | 1.0M tokens | 1.0M tokens |
| Weights | Closed | — |
| Free API (OpenRouter) | No | — |
| Released | Sep 2026 | Apr 2025 |
| At 10M a month | $40.00 | not listed |
Input tokens at list price. No caching, no batch discount.
Where to run it
Quasar Alpha
No hosts listed on OpenRouter.
Per million tokens. Prices and uptime via OpenRouter, checked 28 Sep 2026.
Common questions
What is the difference between Claude Opus 5.5 and Quasar Alpha?
Claude Opus 5.5 is developed by Anthropic while Quasar Alpha is developed by OpenRouter. Claude Opus 5.5 has a 1.0M token context window vs Quasar Alpha's 1.0M. You can compare their actual outputs across 6 challenges on Rival to see how they differ in practice.
Which is better, Claude Opus 5.5 or Quasar Alpha?
It depends on your use case. Claude Opus 5.5 and Quasar Alpha each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 6 challenges so you can judge which fits your needs best.
How can I compare Claude Opus 5.5 and Quasar Alpha on Rival?
This page shows a side-by-side comparison of Claude Opus 5.5 and Quasar Alpha across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.
More comparisons
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- Claude Opus 5.5 vs GPT-6 Sol ProLanded Sep 2026
- Quasar Alpha vs GPT-6 LunaLanded Sep 2026
Same lab, same size, long tail
- Claude Opus 5.5 vs Claude Opus 4.6Same lab
- Claude Opus 5.5 vs Claude Fable 5.1Same lab
- Quasar Alpha vs Ox AlphaSame lab
- Quasar Alpha vs OpenRouter Fusion · Budget (Jun 2026)Same lab
- Quasar Alpha vs Nemotron 3.5 LightningNew provider
- Claude Opus 5.5 vs NVIDIA Nemotron Nano 9B V2New provider
- Claude Opus 5.5 vs Nex-N2.5-Mini (free)Same size
- Claude Opus 5.5 vs Nex-N2.5-Pro (free)Same size
