Ember-1 vs Step-3.5-Flash

Ember-1 and Step-3.5-Flash are closely matched at 43.1 and 37.1 on the LLM Stats Score. Step-3.5-Flash is 34.3x cheaper per token.

Fireworks AI · StepFun · Updated for 2026

Which is better?

Ember-1 and Step-3.5-Flash are closely matched on the overall LLM Stats Score at 43.1 and 37.1.

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, Step-3.5-Flash is roughly 34.3x 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 Ember-1

your work emphasizes coding and agents — it leads those capability indexes
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
you want the most recent training data — it shipped Sep 2026

Choose Step-3.5-Flash

cost matters — it's about 34.3x cheaper per token
you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Better token value: Step-3.5-Flash

Core performance indexes

LLM Stats Score

43.1

#51 · 4 evals

Best

37.1

#82 · 7 evals

Reasoning

38.6

#71 · 3 evals

Best

37.1

#81 · 7 evals

Coding

37.0

#22 · 3 evals

Best

20.2

#109 · 2 evals

Agents

29.7

#44 · 2 evals

Best

15.2

#99 · 3 evals

Cost, coverage & limits

Benchmark wins

1 of 1

Best

0 of 1

Input price

$3.00 / M

$0.10 / M

Best

Output price

$15.00 / M

$0.40 / M

Best

Context window

1,040,000

Best

65,536

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared

Index

Ember-1

Step-3.5-Flash

Tool use

15.9#94 · 2 evals

13.3#108 · 2 evals

Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

4 reported for Ember-1 · 7 for Step-3.5-Flash

1 shared

Ember-1 outperforms in 1 benchmarks (SWE-Bench Verified), while Step-3.5-Flash is better at 0 benchmarks.

Ember-1 significantly outperforms across most benchmarks.

Fri Oct 09 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Step-3.5-Flash costs less

For input processing, Ember-1 ($3.00/1M tokens) is 30.0x more expensive than Step-3.5-Flash ($0.10/1M tokens).

For output processing, Ember-1 ($15.00/1M tokens) is 37.5x more expensive than Step-3.5-Flash ($0.40/1M tokens).

In conclusion, Ember-1 is more expensive than Step-3.5-Flash.*

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

Lowest available price from all providers

Fri Oct 09 2026 • llm-stats.com

Ember-1

Input tokens$3.00

Output tokens$15.00

Best providerFireworks

Step-3.5-Flash

Input tokens$0.10

Output tokens$0.40

Best providerStepFun

Notice missing or incorrect data?

Model Size

Parameter count comparison

2584.0B diff

Ember-1 has 2584.0B more parameters than Step-3.5-Flash, making it 1318.4% larger.

Ember-1

2.8Tparameters

Step-3.5-Flash

196.0Bparameters

2780.0B

Ember-1

196.0B

Step-3.5-Flash

Context Window

Maximum input and output token capacity

Ember-1 accepts 1,040,000 input tokens compared to Step-3.5-Flash's 65,536 tokens. Only Step-3.5-Flash specifies output context (8,192 tokens).

Ember-1

Input1,040,000 tokens

Output- tokens

Step-3.5-Flash

Input65,536 tokens

Output8,192 tokens

Fri Oct 09 2026 • llm-stats.com

License

Usage and distribution terms

Ember-1 is licensed under a proprietary license, while Step-3.5-Flash uses Apache 2.0.

License differences may affect how you can use these models in commercial or open-source projects.

Ember-1

Proprietary

Closed source

Step-3.5-Flash

Apache 2.0

Open weights

Release Timeline

When each model was launched

Ember-1 was released on 2026-09-23, while Step-3.5-Flash was released on 2026-02-02.

Ember-1 is 8 months newer than Step-3.5-Flash.

Ember-1

Sep 23, 2026

2 weeks ago

7mo newer

Step-3.5-Flash

Feb 2, 2026

8 months ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Ember-1 is available from Fireworks. Step-3.5-Flash is available from StepFun.

Ember-1

Fireworks

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

Step-3.5-Flash

StepFun

Input Price:Input: $0.10/1MOutput Price:Output: $0.40/1M

* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Ember-1 and Step-3.5-Flash side-by-side, then vote on the output you prefer.

Ember-1

✓ Preferred

Step-3.5-Flash

Open in Playground

FAQ

Common questions about Ember-1 vs Step-3.5-Flash.

Which is better, Ember-1 or Step-3.5-Flash?

Ember-1 and Step-3.5-Flash are closely matched on the LLM Stats Score at 43.1 and 37.1. Ember-1 is made by Fireworks AI and Step-3.5-Flash is made by StepFun. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Ember-1 compare to Step-3.5-Flash in benchmarks?

Ember-1 scores SWE-Bench Verified: 92.2%, Terminal-Bench 2.1: 82.0%, DeepSWE 1.1: 75.2%, Tau2 Airline: 66.0%. Step-3.5-Flash scores AIME 2025: 97.3%, Tau-bench: 88.2%, LiveCodeBench v6: 86.4%, IMO-AnswerBench: 85.4%, SWE-Bench Verified: 74.4%.

Is Ember-1 cheaper than Step-3.5-Flash?

Step-3.5-Flash is 30.0x cheaper for input tokens. Ember-1 costs $3.00/M input and $15.00/M output via fireworks. Step-3.5-Flash costs $0.10/M input and $0.40/M output via stepfun.

What are the context window sizes for Ember-1 and Step-3.5-Flash?

Ember-1 supports 1.0M tokens and Step-3.5-Flash supports 66K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Ember-1 and Step-3.5-Flash?

Key differences include LLM Stats Score (43.1 vs 37.1), context window (1.0M vs 66K), input pricing ($3.00 vs $0.10/M), licensing (Proprietary vs Apache 2.0). See the full comparison above for benchmark-by-benchmark results.

Who makes Ember-1 and Step-3.5-Flash?

Ember-1 is developed by Fireworks AI and Step-3.5-Flash is developed by StepFun.

Ember-1 vs Step-3.5-Flash