Claude Opus 5.5 vs Ember-1

Claude Opus 5.5 leads the LLM Stats Score 60.5 to 43.6. Ember-1 is 1.3x cheaper per token.

Anthropic · Fireworks AI · Updated for 2026

Which is better?

Claude Opus 5.5 leads the overall LLM Stats Score 60.5 to 43.6, ranking #1 overall.

In the 1 individual benchmarks reported for both models, Ember-1 wins 1; this is a narrower head-to-head signal than the composite indexes.

On price, Ember-1 is roughly 1.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Ember-1 also accepts a larger context window (1,040,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Opus 5.5

overall performance matters — it scores 60.5 and ranks #1 on LLM Stats
your work emphasizes reasoning and coding — it leads those capability indexes

Choose Ember-1

you value its reported benchmark strengths — it wins 1 of 1 exact shared results
cost matters — it's about 1.3x cheaper per token
you process long inputs — it offers a 1,040,000 token context window
you want the most recent training data — it shipped Sep 2026

At a glance

The differences that matter most.

Better token value: Ember-1

Core performance indexes

LLM Stats Score

60.5

#1 · 31 evals

Best

43.6

#46 · 4 evals

Reasoning

59.1

#1 · 22 evals

Best

38.6

#71 · 3 evals

Coding

51.3

#1 · 12 evals

Best

38.0

#20 · 3 evals

Agents

45.5

#1 · 19 evals

Best

31.2

#35 · 2 evals

Cost, coverage & limits

Benchmark wins

0 of 1

1 of 1

Best

Input price

$4.00 / M

$3.00 / M

Best

Output price

$20.00 / M

$15.00 / M

Best

Context window

1,000,000

1,040,000

Best

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared

Index

Claude Opus 5.5

Ember-1

Tool use

32.4#3 · 4 evals

15.9#93 · 2 evals

Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

31 reported for Claude Opus 5.5 · 4 for Ember-1

1 shared

Claude Opus 5.5 outperforms in 0 benchmarks, while Ember-1 is better at 1 benchmark (DeepSWE 1.1).

Ember-1 significantly outperforms across most benchmarks.

Wed Oct 07 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Ember-1 costs less

For input processing, Claude Opus 5.5 ($4.00/1M tokens) is 1.3x more expensive than Ember-1 ($3.00/1M tokens).

For output processing, Claude Opus 5.5 ($20.00/1M tokens) is 1.3x more expensive than Ember-1 ($15.00/1M tokens).

In conclusion, Claude Opus 5.5 is more expensive than Ember-1.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers

Wed Oct 07 2026 • llm-stats.com

Claude Opus 5.5

Input tokens$4.00

Output tokens$20.00

Best providerAnthropic

Ember-1

Input tokens$3.00

Output tokens$15.00

Best providerFireworks

Notice missing or incorrect data?

Context Window

Maximum input and output token capacity

Ember-1 accepts 1,040,000 input tokens compared to Claude Opus 5.5's 1,000,000 tokens. Only Claude Opus 5.5 specifies output context (128,000 tokens).

Claude Opus 5.5

Input1,000,000 tokens

Output128,000 tokens

Ember-1

Input1,040,000 tokens

Output- tokens

Wed Oct 07 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Opus 5.5 supports multimodal inputs, whereas Ember-1 does not.

Claude Opus 5.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Opus 5.5

Text

Images

Audio

Video

Ember-1

Text

Images

Audio

Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Opus 5.5

Proprietary

Closed source

Ember-1

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 5.5 was released on 2026-09-22, while Ember-1 was released on 2026-09-23.

Ember-1 is 0 month newer than Claude Opus 5.5.

Claude Opus 5.5

Sep 22, 2026

2 weeks ago

Ember-1

Sep 23, 2026

2 weeks ago

1d newer

Knowledge Cutoff

When training data ends

Claude Opus 5.5 has a documented knowledge cutoff of 2026-06-01, while Ember-1's cutoff date is not specified.

We can confirm Claude Opus 5.5's training data extends to 2026-06-01, but cannot make a direct comparison without Ember-1's cutoff date.

Claude Opus 5.5

Jun 2026

Ember-1

—

Provider Availability

Claude Opus 5.5 is available from Anthropic. Ember-1 is available from Fireworks.

Claude Opus 5.5

Anthropic

Input Price:Input: $4.00/1MOutput Price:Output: $20.00/1M

Ember-1

Fireworks

Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M

* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Claude Opus 5.5 and Ember-1 side-by-side, then vote on the output you prefer.

Claude Opus 5.5

✓ Preferred

Ember-1

Open in Playground

FAQ

Common questions about Claude Opus 5.5 vs Ember-1.

Which is better, Claude Opus 5.5 or Ember-1?

Claude Opus 5.5 leads the LLM Stats Score 60.5 to 43.6. Claude Opus 5.5 is made by Anthropic and Ember-1 is made by Fireworks AI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Opus 5.5 compare to Ember-1 in benchmarks?

Claude Opus 5.5 scores BenchCAD (with Python tool): 96.2%, Global-MMLU: 94.3%, SWE-bench Multilingual: 93.9%, MILU: 93.1%, ArXivMath: 91.2%. Ember-1 scores SWE-Bench Verified: 92.2%, Terminal-Bench 2.1: 82.0%, DeepSWE 1.1: 75.2%, Tau2 Airline: 66.0%.

Is Claude Opus 5.5 cheaper than Ember-1?

Ember-1 is 1.3x cheaper for input tokens. Claude Opus 5.5 costs $4.00/M input and $20.00/M output via anthropic. Ember-1 costs $3.00/M input and $15.00/M output via fireworks.

What are the context window sizes for Claude Opus 5.5 and Ember-1?

Claude Opus 5.5 supports 1.0M tokens and Ember-1 supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Opus 5.5 and Ember-1?

Key differences include LLM Stats Score (60.5 vs 43.6), context window (1.0M vs 1.0M), input pricing ($4.00 vs $3.00/M), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5.5 and Ember-1?

Claude Opus 5.5 is developed by Anthropic and Ember-1 is developed by Fireworks AI.

Claude Opus 5.5 vs Ember-1