DeepSeek Reasoner API parameters
These are the API parameters modelparams.dev tracks for DeepSeek Reasoner — the settings you send in a request. Each row gives the type, default, valid range or values, and the conditions that gate it. It's the same data the JSON API serves.
This model is retired. Shutdown date: 2026-07-24. Suggested replacement: deepseek/deepseek-v4-flash.
After the parameter count instead — how many weights DeepSeek Reasoner has? That's a different number, and we don't track it. Here's the difference.
Length
1 param
| Parameter | Type | Default | Description | Condition |
|---|---|---|---|---|
|
Max tokens
max_tokens
|
integer (1…+∞) | 4096 | Maximum number of output tokens the model may generate. | — |
Sampling
2 params
| Parameter | Type | Default | Description | Condition |
|---|---|---|---|---|
|
Temperature
temperature
|
number (0…2 step 0.1) | 1 | Controls randomness. In DeepSeek thinking mode this parameter is accepted for compatibility but has no effect. |
Not when thinking.type = "enabled"
|
|
Top P
top_p
|
number (0…1 step 0.01) | 1 | Controls nucleus sampling. In DeepSeek thinking mode this parameter is accepted for compatibility but has no effect. |
Not when thinking.type = "enabled"
|
Reasoning
2 params
| Parameter | Type | Default | Description | Condition |
|---|---|---|---|---|
|
Thinking mode
thinking.type
|
enum (enabled | disabled) | "enabled" | Controls whether DeepSeek uses thinking mode before producing the final answer. | — |
|
Reasoning effort
reasoning_effort
|
enum (high | max) | "high" | Controls DeepSeek thinking effort when thinking mode is enabled. |
Only when thinking.type = "enabled"
|
DeepSeek DeepSeek Reasoner API parameters in brief
DeepSeek DeepSeek Reasoner documents 5 API parameters, grouped by what they control:
-
Length:
max_tokensdefaults to 4096, minimum 1. -
Sampling:
temperaturedefaults to 1, range 0–2, not when thinking.type = "enabled";top_pdefaults to 1, range 0–1, not when thinking.type = "enabled". -
Reasoning:
thinking.typedefaults to "enabled", accepts "enabled", "disabled";reasoning_effortdefaults to "high", accepts "high", "max", only when thinking.type = "enabled".
Frequently asked questions
- Which API parameters does DeepSeek Reasoner support?
- DeepSeek Reasoner accepts 5 API parameters in the request body: max_tokens, temperature, top_p, thinking.type, reasoning_effort.
- What is the default temperature for DeepSeek Reasoner?
- The default temperature for DeepSeek Reasoner is 1, within a valid range of 0 to 2.
- What is the default top_p for DeepSeek Reasoner?
- The default top_p for DeepSeek Reasoner is 1, within a valid range of 0 to 1.
- What is the default max_tokens for DeepSeek Reasoner?
- The default max_tokens for DeepSeek Reasoner is 4096, with a minimum of 1.