Type
Spec
Rate
Input
per 1M prompt tokens
$1.00
Output
per 1M generated tokens
$2.70
Implicit cache read
per 1M cached input tokens
$0.10
Web Search (Linkup)
per call when invoked
$0.013
Step 5 Preview and Step 3.7 Flash side by side: specs, capabilities, parameters, and live pricing from the EmpirioLabs catalog.
StepFun Text GenerationStep 5 Preview and Step 3.7 Flash are both StepFun models in the Text Generation category, available through the EmpirioLabs API.
| Spec | Step 5 Preview | Step 3.7 Flash |
|---|---|---|
| Model ID | step-5-preview | step-3-7-flash |
| Author | StepFun | StepFun |
| Released | Sep 15, 2026 | May 28, 2026 |
| Context window | 1.02M tokens | 256K tokens |
| Max output | 131,072 tokens | 131,072 tokens |
| Input | Text Image Video | Text Image Video |
| Output | Text | Text |
| Structured output | JSON Schema | JSON Mode |
| Region | International | International |
| Endpoints | POST /v1/chat/completions POST /v1/responses POST /v1/messages POST /v1beta/models/step-5-preview:generateContent | POST /v1/chat/completions POST /v1/responses POST /v1/messages POST /v1beta/models/step-3-7-flash:generateContent |
| Capabilities |
Live rates from the EmpirioLabs catalog for both models. Each rate card always matches what the API charges.
Request parameters each model lists on EmpirioLabs, with the allowed values or range where one applies. A dash marks a parameter the model does not list.
| Parameter | Step 5 Preview | Step 3.7 Flash |
|---|---|---|
| temperature | 0 to 2 Default: 0.5 | 0 to 2 Default: 0.5 |
| top_p | 0.01 to 1 Default: 0.9 | 0.01 to 1 Default: 0.9 |
| max_tokens | 1 to 131072 Default: 4096 | 1 to 131072 Default: 4096 |
| stop | array | array |
| frequency_penalty | -2 to 2 Default: 0 | -2 to 2 Default: 0 |
| reasoning_effort | low, medium, high Default: low | low, medium, high Default: low |
| reasoning_format | general, deepseek-style Default: general | general, deepseek-style Default: general |
| tools | array | array |
| tool_choice | string | string |
| response_format | object | object |
| web_search_linkup | boolean Default: false | boolean Default: false |
| disable_formatting | boolean Default: false | boolean Default: false |
Supports text, image, and video input with a 1M token context, parallel function tools, strict JSON schema output, and reasoning_effort low, medium, or high. Prompt-cache hits are billed at the cache-read rate. Video input supports MP4 under 128 MB, with clips under 5 minutes recommended. This is a preview release, so its behavior and identifier may change.
Supports text, image, and video input with 256K context, function tools, JSON object mode, reasoning_effort low, medium, or high, and optional Linkup web search. Video input supports MP4 under 128 MB, with clips under 5 minutes recommended.
Step 5 Preview serves the OpenAI-compatible Chat Completions API. Point any OpenAI SDK at https://api.empiriolabs.ai/v1 with your EmpirioLabs API key and use the model id step-5-preview. Both models are called through the same endpoint. Set model to step-5-preview or step-3-7-flash. Get an API key from the EmpirioLabs dashboard.
curl https://api.empiriolabs.ai/v1/chat/completions \
-H "Authorization: Bearer $EMPIRIOLABS_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "step-5-preview",
"messages": [
{"role": "user", "content": "Write a haiku about the ocean."}
]
}'Step 5 Preview is the newer release (Sep 15, 2026); Step 3.7 Flash was released on May 28, 2026. Step 5 Preview has the larger context window: 1.02M tokens, against 256K for Step 3.7 Flash. Capabilities listed only for Step 3.7 Flash: web search. The specs, rate cards, and parameters on this page come from the live EmpirioLabs catalog.
Step 5 Preview is the newer release (Sep 15, 2026); Step 3.7 Flash was released on May 28, 2026.
Step 3.7 Flash lists the lower rate for Input (per 1M prompt tokens) and Output (per 1M generated tokens). Both live rate cards are on this page and always match what the API charges.
Yes. Both models use POST /v1/chat/completions with the same EmpirioLabs API key, so most integrations switch by changing the model value. Check the parameters table on this page first if you rely on a model-specific parameter.
Yes. Open each model in the EmpirioLabs playground and run the same prompt on both, with the parameters the API exposes.
Check out our pricing or reach out if you want your own model deployed on our stack.