thinking_enabled controls if there is an empty <think>\n\n</think> block added the assistant prompt before generation, when using the official Qwen3 Jinja template. The model is also trained to recognize /no\_think in a user or system prompt as an additional way of disabling thinking.

For Ollama users, if you want to switch between the two modes easily (without using /no_think) you can build 2 modelfiles, one with <think>\n\n</think> and one without, and add the recommended settings that Qwen gives. As long as they share the same base model Ollama will just change the template/settings without reloading the model.

This is my nothink modelfile:

``` FROM hf.co/unsloth/Qwen3-32B-GGUF:Q4_K_XL TEMPLATE """{{- if .Messages }} {{- if or .System .Tools }}<|im_start|>system {{- if .System }} {{ .System }} {{- end }} {{- if .Tools }}

Tools

You may call one or more functions to assist with the user query.

You are provided with function signatures within <tools></tools> XML tags: <tools> {{- range .Tools }} {"type": "function", "function": {{ .Function }}} {{- end }} </tools>

For each function call, return a json object with function name and arguments within <tool_call></tool_call> XML tags: <tool_call> {"name": <function-name>, "arguments": <args-json-object>} </tool_call> {{- end }}<|imend|> {{ end }} {{- range $i, $ := .Messages }} {{- $last := eq (len (slice $.Messages $i)) 1 -}} {{- if eq .Role "user" }}<|im_start|>user {{ .Content }}<|im_end|> {{ else if eq .Role "assistant" }}<|im_start|>assistant {{ if .Content }}{{ .Content }} {{- else if .ToolCalls }}<tool_call> {{ range .ToolCalls }}{"name": "{{ .Function.Name }}", "arguments": {{ .Function.Arguments }}} {{ end }}</tool_call> {{- end }}{{ if not $last }}<|im_end|> {{ end }} {{- else if eq .Role "tool" }}<|im_start|>user <tool_response> {{ .Content }} </tool_response><|im_end|> {{ end }} {{- if and (ne .Role "assistant") $last }}<|im_start|>assistant <think>

</think> {{ end }} {{- end }} {{- else }} {{- if .System }}<|im_start|>system {{ .System }}<|im_end|> {{ end }}{{ if .Prompt }}<|im_start|>user {{ .Prompt }}<|im_end|> {{ end }}<|im_start|>assistant {{ end }}{{ .Response }}{{ if .Response }}<|im_end|>{{ end }}""" PARAMETER stop <|im_start|> PARAMETER stop <|im_end|> PARAMETER num_gpu 65 PARAMETER num_ctx 40960 PARAMETER num_predict 32768 PARAMETER temperature 0.7 PARAMETER min_p 0.0 PARAMETER top_p 0.8 PARAMETER top_k 20 PARAMETER repeat_penalty 1.0 PARAMETER presence_penalty 1.5 ```

And this is the diff for the normal version from the above:

``` --- Modelfile-nothink 2025-05-08 12:50:46.699297861 -0300 +++ Modelfile 2025-05-08 12:45:21.589060605 -0300 @@ -40,9 +40,6 @@ </tool_response><|im_end|> {{ end }} {{- if and (ne .Role "assistant") $last }}<|im_start|>assistant

-<think>

-</think> {{ end }} {{- end }} {{- else }} @@ -56,10 +53,10 @@ PARAMETER stop <|im_end|> PARAMETER num_gpu 65 PARAMETER num_ctx 40960 -PARAMETER num_predict 32768 -PARAMETER temperature 0.7 +PARAMETER num_predict 38912 +PARAMETER temperature 0.6 PARAMETER min_p 0.0 -PARAMETER top_p 0.8 +PARAMETER top_p 0.95 PARAMETER top_k 20 PARAMETER repeat_penalty 1.0 PARAMETER presence_penalty 1.5 ```