StepFun, released Jan 29, 2026

Step 3.5 Flashprice, context, benchmarks and release details

Provisional: not enough results to rank yet Open weights 88% confidence, 2 of 3 expected sources in

53.0

SI Score

#98 of 142 ranked models

Input, per 1M tokens: $0.10
Output, per 1M tokens: $0.30
Context window: 256K
Max output: 256K
Released: Jan 29, 2026

How the score breaks down

Coding 50.9

Math —

Preference 73.4

Reasoning —

Weights: reasoning 30%, math 15%, coding 40%, preference 15%. Results use fixed 0–100 scales before averaging, and thin evidence is pulled toward 50. Method si-v3-retained-evidence-2, computed Oct 9, 2026, 05:13 UTC.

Around it on the leaderboard

96 DeepSeek V3.2 53.3
97 GLM-4.7-Flash 53.3
98 Step 3.5 Flash 53.0
99 Qwen3 30B A3B 52.6
100 GPT OSS 20B 52.5

Full leaderboard

Benchmark results

3 benchmarks, 3 results

Each row shows the best published result. Where a model was tested at several settings, such as reasoning effort, open the row to see each one. Hover or tap a value for its source.

SWE-bench Verifiedcoding 74.4% 74.4

Terminal-Benchcoding 27.3% 27.3

LMArena Textpreference 1402.9 elo 73.4

Normalization uses a fixed 0–100 scale for each unit, independent of other models. Compare evaluation conditions before reading a small gap as decisive. “Lab-reported” marks the provider's own published figure.

Details and sources

Open weights: Yes
License: not yet reported
Input modalities: text
First seen by SuperIndex: Oct 8, 2026
Coverage: 70% of expected source weight

Reported (2)

Official model cards via models.devOct 8, 2026
LMArena / ArenaOct 8, 2026

Awaiting (1)

LiveBench30% of weight

Confidence rises as pending sources publish. Some sources never cover some models, so confidence reaches 100% at 80% of expected weight.