Step 3.5 Flash 2603

Step 3.5 Flash 2603: a AI model from stepfun, ~256K context, knowledge cutoff 2025-01

Published

scheduleReleased：April 2, 2026

Step 3.5 Flash 2603 is a AI model from stepfun (~256K context, input around $0.1/1M tokens). Suitable for assistants, content generation, knowledge Q&A and business automation

descriptionOverview

Overview

Step 3.5 Flash 2603 is provided by stepfun, model ID step-3.5-flash-2603

Key specs

Context: 256K tokens
Max output: 256K tokens
Knowledge cutoff: 2025-01
Input price: $0.1/1M
Output price: $0.3/1M

Best for

Consider Step 3.5 Flash 2603 when comparing context length, pricing, multimodal support and relay availability

lightbulbUse cases

Assistants and customer support
Content generation and rewriting
Knowledge Q&A and summarization
Structured extraction

thumb_upStrengths

Very long context (~256K), good for long documents and codebases
Open weights, can be self-hosted
High single-response output limit (~256K)

infoLimitations

Knowledge cutoff 2025-01; newer facts need external retrieval
Pricing and availability vary by upstream and relay; verify with official docs and tests

linkReferences

open_in_newhttps://platform.stepfun.com/docs/overview/concept