Claude Sonnet 5.5 vs Ember-1

Claude Sonnet 5.5 leads the LLM Stats Score 58.5 to 43.6. Claude Sonnet 5.5 is 1.5x cheaper per token.

Anthropic · Fireworks AI · Updated for 2026

Which is better?

Claude Sonnet 5.5 leads the overall LLM Stats Score 58.5 to 43.6, ranking #2 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, Claude Sonnet 5.5 is roughly 1.5x 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 Sonnet 5.5

overall performance matters — it scores 58.5 and ranks #2 on LLM Stats
your work emphasizes reasoning — it leads those capability indexes
cost matters — it's about 1.5x cheaper per token
you want the most recent training data — it shipped Sep 2026

Choose Ember-1

you value its reported benchmark strengths — it wins 1 of 1 exact shared results
you process long inputs — it offers a 1,040,000 token context window

At a glance

The differences that matter most.

Better token value: Claude Sonnet 5.5

Core performance indexes

LLM Stats Score

58.5

#2 · 31 evals

Best

43.6

#46 · 4 evals

Reasoning

57.1

#2 · 23 evals

Best

38.6

#71 · 3 evals

Coding

48.9

#2 · 13 evals

Best

38.0

#20 · 3 evals

Agents

42.7

#3 · 19 evals

Best

31.2

#35 · 2 evals

Cost, coverage & limits

Benchmark wins

0 of 1

1 of 1

Best

Input price

$2.00 / M

Best

$3.00 / M

Output price

$10.00 / M

Best

$15.00 / M

Context window

1,000,000

1,040,000

Best

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared

Index

Claude Sonnet 5.5

Ember-1

Tool use

34.1#2 · 4 evals

15.9#93 · 2 evals

Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

47 reported for Claude Sonnet 5.5 · 4 for Ember-1

1 shared

Claude Sonnet 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

Claude Sonnet 5.5 costs less

For input processing, Claude Sonnet 5.5 ($2.00/1M tokens) is 1.5x cheaper than Ember-1 ($3.00/1M tokens).

For output processing, Claude Sonnet 5.5 ($10.00/1M tokens) is 1.5x cheaper than Ember-1 ($15.00/1M tokens).

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

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

Lowest available price from all providers

Wed Oct 07 2026 • llm-stats.com

Claude Sonnet 5.5

Input tokens$2.00

Output tokens$10.00

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 Sonnet 5.5's 1,000,000 tokens. Only Claude Sonnet 5.5 specifies output context (128,000 tokens).

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

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

Claude Sonnet 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 Sonnet 5.5

Proprietary

Closed source

Ember-1

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Sonnet 5.5 was released on 2026-09-28, while Ember-1 was released on 2026-09-23.

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

Claude Sonnet 5.5

Sep 28, 2026

1 weeks ago

5d newer

Ember-1

Sep 23, 2026

2 weeks ago

Knowledge Cutoff

When training data ends

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

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

Claude Sonnet 5.5

Jun 2026

Ember-1

—

Provider Availability

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

Claude Sonnet 5.5

Anthropic

Input Price:Input: $2.00/1MOutput Price:Output: $10.00/1M

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 Sonnet 5.5 and Ember-1 side-by-side, then vote on the output you prefer.

Claude Sonnet 5.5

✓ Preferred

Ember-1

Open in Playground

FAQ

Common questions about Claude Sonnet 5.5 vs Ember-1.

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

Claude Sonnet 5.5 leads the LLM Stats Score 58.5 to 43.6. Claude Sonnet 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 Sonnet 5.5 compare to Ember-1 in benchmarks?

Claude Sonnet 5.5 scores BenchCAD (with Python tool): 96.3%, ArXivMath (with tools): 95.2%, Global-MMLU: 92.1%, MILU: 91.6%, SWE-bench Multilingual: 90.3%. 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 Sonnet 5.5 cheaper than Ember-1?

Claude Sonnet 5.5 is 1.5x cheaper for input tokens. Claude Sonnet 5.5 costs $2.00/M input and $10.00/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 Sonnet 5.5 and Ember-1?

Claude Sonnet 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 Sonnet 5.5 and Ember-1?

Key differences include LLM Stats Score (58.5 vs 43.6), context window (1.0M vs 1.0M), input pricing ($2.00 vs $3.00/M), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Sonnet 5.5 and Ember-1?

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

Claude Sonnet 5.5 vs Ember-1