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Familyroot · Step

Step3.5

All 3 models in the terminal →

first seen 11 Sept 2026

family_01M2A55V0XM2EBG9CQ8WW1A1DC

Models
3
First release
29 Jan 2026
Latest release
25 Feb 2026
Parameters
121B – 149.4B
Artifacts
0
Providers
1

Releases

Family releases by statusActiveDeprecatedFeb 26Feb 26Feb 26Feb 26Step 3.5 Flash — 29 Jan 2026Step-3.5-Flash-REAP-121B-A11B — 25 Feb 2026Step-3.5-Flash-REAP-149B-A11B — 25 Feb 2026

3 dated releases · dot size = best benchmark rank of the member

Members 3

Family members
ModelParamsContextOpennessLicenceReleasedStatusBest rankCompare
Step-3.5-Flash-REAP-121B-A11BCerebras Systems121B11B active—Open weightsOther25 Feb 2026Active—
Step-3.5-Flash-REAP-149B-A11BCerebras Systems149.4B11B active—Open weightsOther25 Feb 2026Active—
Step 3.5 FlashStepFun—262.1KOpen weights—29 Jan 2026Deprecated#28 τ²-bench

Lineage among members 2 relations

Open in Graph →
Lineage of the Step3.5 familyStep-3.5-Flash-REAP-121B-A11B fine-tuned from Step 3.5 FlashStep-3.5-Flash-REAP-149B-A11B fine-tuned from Step 3.5 FlashStep 3.5 FlashStep 3.5 FlashStep-3.5-Flash-REAP-121B-…121BStep-3.5-Flash-REAP-121B-A11BStep-3.5-Flash-REAP-149B-…149.4BStep-3.5-Flash-REAP-149B-A11B

Benchmark progress

Benchmark progress needs at least two dated members with a rank on the same benchmark. Ranks (not scores) are what the family endpoint provides.

Aggregates are computed from the members' sourced claims; members without a release date or parameter count are left out of the range and timeline rather than guessed. Methodology →