Step 3.7 Flash (Reasoning)

by StepFun

Step 3.7 Flash (Reasoning) is a reasoning model from StepFun, released on June 10, 2026. It has a 262K-token context window and can generate up to 262K output tokens. API pricing is $0.2 per 1M input tokens and $1.15 per 1M output tokens. It ranks #81 of 220 models by Intelligence Score with a score of 29.7.

Step 3.7 Flash is an open-source multimodal reasoning model by StepFun with 198B total parameters (11B active) using Mixture of Experts. It accepts text and image inputs and features a 256K context window, selectable reasoning effort, tool calling, and agentic capabilities for coding and search workflows, scoring 80.9% on GPQA Diamond and 56.3% on SWE-bench Pro.

Key specs

ProviderStepFun
Release date2026-06-10
Licenseopen source
Context window262K tokens
Max output262K tokens
Input price$0.2 / 1M tokens
Output price$1.15 / 1M tokens
Intelligence Score29.7
Coding index19.2

Quick answers

What is the context window of Step 3.7 Flash (Reasoning)?

Step 3.7 Flash (Reasoning) has a context window of 262K tokens, with a maximum output of 262K tokens per response.

How much does Step 3.7 Flash (Reasoning) cost?

Step 3.7 Flash (Reasoning) costs $0.2 per 1M input tokens and $1.15 per 1M output tokens through the API.

Is Step 3.7 Flash (Reasoning) open source?

Yes. Step 3.7 Flash (Reasoning) is an open model released under the open source license.

When was Step 3.7 Flash (Reasoning) released?

StepFun released Step 3.7 Flash (Reasoning) on June 10, 2026.

How does Step 3.7 Flash (Reasoning) compare to Claude Opus 5.5 (Reasoning)?

Step 3.7 Flash (Reasoning) scores 29.7 on the Intelligence Score versus 60.5 for Claude Opus 5.5 (Reasoning), the current #1. Input pricing is $0.2 vs $4 per 1M tokens.

Compare on the AI leaderboard · All AI models

More models from StepFun