StepFun
Updated May 2026Step
Cost-conscious multimodal models from one of China's fastest labs
StepFun builds text, vision, and multimodal models with a strong emphasis on efficient architecture and production APIs. Its Step series shows how newer labs compete by balancing capability, latency, and deployment cost instead of chasing only the biggest parameter count.
Variants
4
Best at
OpenAI-compatible API surface
Max context
128K
tokens
Pricing
Step API
varies
per hosted usage
Variants
Sort the table by context window or cost to find the right variant. Click any version below for a battle card with ranks, pricing notes, and official links.
| Modalities | ||||
|---|---|---|---|---|
Step-3.5 Flash step-3.5-flash | 128K | varies / varies | 2026 | textvisioncode |
Step3 step-3 | 64K | varies / varies | 2025 | textvision |
Step-2 step-2-16k | 16K | varies / varies | 2024 | textcode |
Step-1 step-1-8k | 8K | varies / varies | 2024 | text |
Battle card
Context rank
#3
within Step
Capability rank
#2
modalities + reasoning
Weights
Closed
API/app access
Best fights to pick
- Chinese-language chat
- business writing
- agent prototypes
Rankings are Tendril directory ranks, computed from the model data shown here. Public benchmark leaderboards change often, so official docs and current benchmark pages should be checked before buying or deploying.
Learn
Lessons about this model
Structured lessons that cover Step directly or put it in context alongside its rivals.
Step: Family Map
Step: Flagship Picker
Step: Cost And Context
Step: Reasoning Mode
Step: Multimodal Workflows
Step: Coding And Software Tasks
Step: Agents And Tool Use
Step: Local Or Private Deployment
Step: Benchmarks And Reality Checks
Step: Safety And Limits
Step: Prompt Recipes
Step: Industry Use Cases
Step: Compare Against Rivals
Step: Build A Mini Workflow
Step: Capstone Selection Memo
Check yourself
Quizzes
Short, mixed-difficulty quiz sets on Step and its model family.
Step Model Family Quiz
5 questions
A short quiz on where Step fits, which variants matter, and how to choose it responsibly.
Start quiz →Hands-on
Try these prompts
Ready-made prompts that show Step at its best. Use them in your own AI workspace, then compare the output with what you learned in Tendril.
Step same-task bakeoff
BuildersCompare Step against a cheaper and stronger rival on one real task.
Use Step for this task, then compare with one cheaper model and one stronger model: summarize a 10-page policy document into risks, decisions, owners, and open questions.
Step failure-mode log
CreatorsTrack where Step fails instead of only saving the best output.
Run this task three times. For every answer, mark failures as factual error, formatting error, weak reasoning, refusal, or missing citation.
Print & keep
Printable reference
One-page summaries and flowcharts — great for desks, classrooms, or study sessions.
Go deeper
Official resources
Straight from the lab — docs, API references, and the chat surfaces you can try today.
Strengths
- OpenAI-compatible API surface
- cost-sensitive architecture
- multimodal research direction
Limits
- shorter contexts on older production models
- smaller global ecosystem
- documentation depth varies by language