Claude Opus 5.5 vs Ember-1: Specs & Benchmark Comparison
Claude Opus 5.5 is developed by Anthropic, while Ember-1 comes from Fireworks AI. Both were released in September 2026. Ember-1 has a published size of about 2.8 trillion parameters; Anthropic has not disclosed the parameter count of Claude Opus 5.5.
We have 31 benchmark results for Claude Opus 5.5 and 4 benchmark results for Ember-1, but they overlap on a single test: DeepSWE 1.1, where Ember-1 scores 75.2% against 74.2%.
Ember-1 is the cheaper API at $3 per million input tokens and $15 per million output tokens, about 33% below Claude Opus 5.5 at $4 and $20. Both accept a context window of about 1M tokens. Claude Opus 5.5 accepts text and images as input, while Ember-1 accepts text.
| Characteristic | Claude Opus 5.5 | Ember-1 |
|---|---|---|
| Company | Anthropic | Fireworks AI |
| Release Date | September 22, 2026 | September 23, 2026 |
| Parameters | — | 2.8T |
| Multimodal | Yes | No |
| Context (input) | 1.0M | 1.0M |
| Context (output) | 128K | — |
| Input Price / 1M | $4.00 | $3.00 |
| Output Price / 1M | $20.00 | $15.00 |
| Average Score | 71.1% | 78.8% |
| Benchmarks | ||
| DeepSWE 1.1 | 74.2% | 75.2% |
Visual Benchmark Comparison
Verdict
Both models show equal results — the choice depends on your specific use case.
Both models show comparable average scores: Claude Opus 5.5 — 0.7, Ember-1 — 0.8.
Ember-1 is 1.3x cheaper: input $3.00/1M vs $4.00/1M tokens.
Claude Opus 5.5 supports a larger context: 1M vs 1M tokens.
Both models were released around the same time: 9/22/2026 and 9/23/2026.
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Frequently Asked Questions
Which is better for coding — Claude Opus 5.5 or Ember-1?
Which model is cheaper — Claude Opus 5.5 or Ember-1?
Which has a larger context window — Claude Opus 5.5 or Ember-1?
The Claude Opus 5.5 and Ember-1 comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Claude Opus 5.5 or Ember-1 page. See also the complete list of AI model comparisons.