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 Seed 2.1 Turbo side by side: specs, capabilities, parameters, and live pricing from the EmpirioLabs catalog.
StepFun 
ByteDance Text GenerationStep 5 Preview from StepFun and Seed 2.1 Turbo from ByteDance are both in the Text Generation category, available through the EmpirioLabs API.
| Spec | Step 5 Preview | Seed 2.1 Turbo |
|---|---|---|
| Model ID | step-5-preview | seed-2-1-turbo |
| Author | StepFun | ByteDance |
| Released | Sep 15, 2026 | Jul 13, 2026 |
| Context window | 1.02M tokens | 229.1K tokens |
| Max output | 131,072 tokens | 65,536 tokens |
| Input | Text Image Video | Text Image Video |
| Output | Text | Text |
| Structured output | JSON Schema | JSON Schema |
| Region | International | Malaysia |
| 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/seed-2-1-turbo: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 | Seed 2.1 Turbo |
|---|---|---|
| temperature | 0 to 2 Default: 0.5 | - |
| top_p | 0.01 to 1 Default: 0.9 | - |
| max_tokens | 1 to 131072 Default: 4096 | 1 to 65536 |
| stop | array | string |
| frequency_penalty | -2 to 2 Default: 0 | -2 to 2 Default: 0 |
| reasoning_effort | low, medium, high Default: low | low, medium, high Default: high |
| reasoning_format | general, deepseek-style Default: general | - |
| tools | array | - |
| tool_choice | string | - |
| response_format | object | enum |
| web_search_linkup | boolean Default: false | - |
| disable_formatting | boolean Default: false | - |
| presence_penalty | - | -2 to 2 Default: 0 |
| enable_thinking | - | boolean Default: true |
| enable_web_search | - | boolean Default: false |
| max_tool_calls | - | 1 to 10 Default: 3 |
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.
Per-token pricing is flat across the full context window, with no higher rate above 128K. Reasoning is on by default; set enable_thinking to false to answer directly without it.
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 seed-2-1-turbo. 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."}
]
}'Prompt tests and comparison runs that cover both models.
Step 5 Preview is the newer release (Sep 15, 2026); Seed 2.1 Turbo was released on Jul 13, 2026. Step 5 Preview has the larger context window: 1.02M tokens, against 229.1K for Seed 2.1 Turbo. Step 5 Preview returns up to 131,072 output tokens per response, Seed 2.1 Turbo up to 65,536. 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); Seed 2.1 Turbo was released on Jul 13, 2026.
Step 5 Preview lists the lower rate for Output (per 1M generated tokens). Seed 2.1 Turbo lists the lower rate for Input (per 1M prompt 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.
