Install Ollama
Download and install Ollama from the official download page at https://ollama.com/download, choosing the installer for your operating system (Windows, macOS, or Linux).
Text / Intermediate
Set up private chat with gpt-oss · 20B
Install Ollama, pull the gpt-oss:20b model, launch a local private chat session, send a first prompt, and verify the model responds.
EstimatedSource checked 9/24/2026
LOCALRENTED GPU
Before you begin
- Difficulty
- Intermediate
- Software
- Ollama, gpt-oss:20b
- Hardware
- For the publisher's 14.0 GB Ollama text package at a short 4K context, we estimate at least 22 GB GPU memory or 32 GB Apple unified memory. For a more comfortable starting point, use 32 GB GPU memory or 40 GB unified memory. These are capacity estimates, not speed tests; longer context and other apps need additional headroom.
TEXT / OLLAMASOURCE-LINKED SETUP
Set up private chat with gpt-oss · 20B, step by step.
Install Ollama, pull the gpt-oss:20b model, launch a local private chat session, send a first prompt, and verify the model responds.
Choose a package Run its commands Check the result
01
BEFORE YOU BEGIN
The documented package
This setup uses the package documented for this task. Review its source and supported platforms before starting.
Save your machine in My Hardware to get an automatic starting choice. You can always choose any package yourself.
CURRENT SETUP
View weight source gpt-oss · 20B · official
For the publisher's 14.0 GB Ollama text package at a short 4K context, we estimate at least 22 GB GPU memory or 32 GB Apple unified memory. For a more comfortable starting point, use 32 GB GPU memory or 40 GB unified memory. These are capacity estimates, not speed tests; longer context and other apps need additional headroom.
02
THE WORKFLOW
Set up gpt-oss · 20B on your machine
Pick your operating system. Every command below is for the selected package and runtime.
Install Ollama for this operating system before running the model command.
Pull the gpt-oss:20b model
Open a terminal and download the model weights into your local Ollama library.
ollama pull gpt-oss:20bStart an interactive chat session
Run the model in Ollama’s interactive chat mode. Leave this terminal open; it is your private local chat session.
ollama run gpt-oss:20bSend your first prompt
At the Ollama prompt, type a short question to confirm the model is responding.
Explain quantum mechanics clearly and concisely.Verify the model response
Read the reply printed below your prompt. A successful setup shows a generated answer from gpt-oss:20b. If you see model-generated text that addresses your question, the model is running and responding locally.
03
SUCCESS CHECK · gpt-oss · 20B
Check the first local reply
Ask a short question with a known answer. Confirm the selected local model responds and verify the answer yourself before using it for private work.
This is a source-linked setup, not a YouRunAI hardware test. Confirm your exact runtime version, package, and output before relying on it.
When it doesn’t go to plan
The ollama command is not recognized after installation.
Close and reopen your terminal so the updated PATH is loaded, then run the command again.
The model pull is interrupted or fails.
Run ollama pull gpt-oss:20b again; Ollama resumes from the downloaded portions.
The chat starts but no useful response appears.
Make sure you are running the model with Ollama, which applies the Harmony response format. The gpt-oss model must be used with the Harmony format to work correctly.
The model is too slow or uses too much memory.
Try the lower reasoning effort setting by including “Reasoning: low” in the system prompt, or ensure your machine has enough free memory for the 20B model.
REFERENCE LIBRARY
3 SOURCESSources and files
Original instructions, model files, and compatibility notes behind this setup.
The model behind this workflow
gpt-oss · 20BWill it run on your machine?
Save your machine to see a personalized rating and its reasoning.
Add my hardwareKeep exploring
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