Modeldex

StepFun · Text line

Step Flash

2 stages over 4 months, from Step 3.5 Flash in Jan 2026 to Step 3.7 Flash in May 2026.

Evolution chamber01 / 02
StepFun

Step 3.5 Flash

CTX256K
64Quality
Reasoning · Tools
TextInput$0.10/M
TextOutput$0.30/M

StepFun flash lane for quick multimodal reasoning and coding assistance

Open weightsApache 2.0768/1040
Ready to evolve

Every generation. A new possibility.

Step 3.5 Flash · Jan 2026
View model : Step 3.5 Flash

2 stages, from Step 3.5 Flash (Jan 2026) to Step 3.7 Flash (May 2026). Press Evolve to watch each step.

How it grew

Context window

  1. 256Kv3.5
  2. 256Kv3.7

Max output

  1. 256Kv3.5
  2. 256Kv3.7

Output priceper 1M tokens, lower is better

  1. $0.30v3.5
  2. $1.11v3.7

Parameters

  1. 199Bv3.5
  2. 201Bv3.7

Downloadslast 30 days

  1. 260Kv3.5
  2. 19Kv3.7

Every stage

  1. v3.5 Stage 1

    StepFun

    Step 3.5 Flash

    CTX256K
    64Quality
    Reasoning · Tools
    TextInput$0.10/M
    TextOutput$0.30/M

    StepFun flash lane for quick multimodal reasoning and coding assistance

    Open weightsApache 2.0768/1040
    +1 more in v3.5

  2. v3.7 Stage 2

    StepFun

    Step 3.7 Flash

    CTX256K
    Reasoning · Vision · Tools
    TextImageVideoInput$0.18/M
    TextOutput$1.11/M

    Newer StepFun flash model for faster agents, coding, and multimodal prompts

    Open weightsApache 2.0910/1040

More StepFun lines

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