xAI · model

`grok-4-1-fast-non-reasoning` deprecation: shutdown date & replacement

Shut down May 15, 2026

Retired May 15, 2026 12:00 PM PT; slug keeps resolving and redirects to grok-4.3 with none reasoning effort, billed at the target's pricing.

How to migrate off grok-4-1-fast-non-reasoning

Find every place that references it:

grep -rn --exclude-dir={node_modules,.git,dist} "grok-4-1-fast-non-reasoning" .

Replace the model ID:

- model: "grok-4-1-fast-non-reasoning"
+ model: "grok-4.3"

Re-run your evals or a sample of real prompts — output style, token usage and pricing can change between models.
Check config outside code too: environment variables, feature flags, prompt-management tools, and fine-tuned model references.
Deploy before May 15, 2026, and add the CI scanner so it cannot come back.

Is grok-4-1-fast-non-reasoning deprecated?

Yes. xAI has deprecated grok-4-1-fast-non-reasoning. It was shut down on May 15, 2026.

When does grok-4-1-fast-non-reasoning shut down?

May 15, 2026, according to xAI's official deprecation notice.

What should I use instead of grok-4-1-fast-non-reasoning?

xAI recommends grok-4.3. Switch the model ID and re-test your prompts, since outputs, pricing and limits can differ.

What happens to requests to grok-4-1-fast-non-reasoning after the shutdown?

Requests using the retired model ID fail with an error, so any code still calling it breaks. Update and deploy before the shutdown date.