AnthropicClaude Opus 5.5 alternatives
Data as of 2 Nov 2026 · ranked on the BenchLeader Index
As of 2 Nov 2026, Claude Opus 5.5 by Anthropic scores 69.2 on the BenchLeader Index at $8.00 per 1M tokens blended. Nothing ranked scores higher; GPT-6.1 Sol is the best cheaper model within 4 points (67.2 at $4.00); Kimi K3 is the best open-weights option (62.1).
Cheaper, nearly as good
Within 4 Index points, for less per token.
- GPT-6.1 Sol OpenAI compare67.2 · $4.00
- Gemini 4 Argon Google compare65.9 · $4.00
- GPT-6.1 Terra OpenAI compare65.2 · $2.00
Open weights
The best models whose weights you can run yourself.
Every alternative side by side
| Model | Index | $ / 1M blended | Tokens / s | Why |
|---|---|---|---|---|
| Claude Opus 5.5 (this model) | 69.2 | $8.00 | 96 | – |
| GPT-6.1 Sol | 67.2 | $4.00 | 87 | cheaper |
| Gemini 4 Argon | 65.9 | $4.00 | 83 | cheaper |
| GPT-6.1 Terra | 65.2 | $2.00 | 107 | cheaper |
| Kimi K3 | 62.1 | $6.00 | 66 | open weights |
| GLM-5 | 60.2 | $1.55 | 62 | open weights |
| GLM 5.2 | 60.1 | $2.15 | 89 | open weights |
Prices are list prices blended three input tokens to one output; speeds are measured medians, credited on each model page. The Index is BenchLeader's own, from independent benchmarks.
Questions people ask
- What is the best alternative to Claude Opus 5.5?
- No ranked model scores higher than Claude Opus 5.5 on the BenchLeader Index. The best cheaper model within 4 points is GPT-6.1 Sol (67.2, $4.00 per 1M tokens).
- Is there a cheaper alternative to Claude Opus 5.5?
- Yes: GPT-6.1 Sol (67.2, $4.00), Gemini 4 Argon (65.9, $4.00) and GPT-6.1 Terra (65.2, $2.00), each within 4 Index points and cheaper than Claude Opus 5.5's $8.00.
- Is there an open-source alternative to Claude Opus 5.5?
- The best open-weights models on the BenchLeader Index are Kimi K3 (62.1), GLM-5 (60.2) and GLM 5.2 (60.1). You can download and run them yourself; check each licence on its model page.
- How are these alternatives chosen?
- From the models ranked on the BenchLeader Index today: the ones just above Claude Opus 5.5, cheaper ones within 4 points, ones at least 1.5× as fast within 4 points, and the best open-weights models. Prices are list prices blended three input tokens to one output.
Related: Claude Opus 5.5, alternatives to other models, best value models.