Claude Opus 5.5 is Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work, succeeding Claude Opus 5. It is particularly strong at multi-step changes in large codebases, code...
Model details →Anthropic: Claude Opus 5.5 vs Fireworks: Ember-1
Fireworks: Ember-1 wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
Ember-1 is a specialized reasoning model from Fireworks Research, built on [Kimi K3](https://openrouter.ai/moonshotai/kimi-k3). It is designed to make every token go further: it produces shorter reasoning traces, using roughly 40%...
Model details →Side-by-side comparison
| Capability | Anthropic: Claude Opus 5.5 | Fireworks: Ember-1 | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1M | 1.0M | 🏆 Fireworks: Ember-1 |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $4.00 | $3.00 | 🏆 Fireworks: Ember-1 |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $20.00 | $15.00 | 🏆 Fireworks: Ember-1 |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | Yes | Tie |
| Vision input Accepts image inputs alongside text. | Yes | Yes | Tie |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | Yes | Tie |
Frequently asked questions
Is Anthropic: Claude Opus 5.5 better than Fireworks: Ember-1?
Fireworks: Ember-1 wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between Anthropic: Claude Opus 5.5 and Fireworks: Ember-1?
Input: $4.00 vs $3.00 per 1M tokens. Output: $20.00 vs $15.00 per 1M tokens.
What context windows do Anthropic: Claude Opus 5.5 and Fireworks: Ember-1 support?
Anthropic: Claude Opus 5.5 supports up to 1M tokens. Fireworks: Ember-1 supports up to 1.0M tokens.
Do both Anthropic: Claude Opus 5.5 and Fireworks: Ember-1 support tool calling?
Anthropic: Claude Opus 5.5: yes. Fireworks: Ember-1: yes.