WhichBot › What replaced it › What replaces o3?
Last checked Oct 28, 2026 · plain English · no paid picks
What replaces o3?
Short answer: OpenAI names GPT-5.6 Sol. o3 shuts down in OpenAI's developer service on Dec 11, 2026. OpenAI's newest main model in our directory is GPT-6.1 Sol.
What to do: Developers: move off o3 before Dec 11, 2026.
The facts
| Old | o3 |
|---|---|
| Status | Retiring. Developer service shutdown Dec 11, 2026 |
| Replaced by | GPT-5.6 Sol |
| Official source | platform.openai.com |
| Last checked | Oct 28, 2026 |
Current options at a glance
| GPT-6.1 Sol | GPT-6 Astra | |
|---|---|---|
| What it is | OpenAI's main model on paid ChatGPT plans | OpenAI's model for hard reasoning |
| Made by | OpenAI | OpenAI |
| Price | Developer price: $2 in and $10 out per million tokens | Developer price: $10 in and $50 out per million tokens |
| Good at | Reads up to 1,050,000 tokens at once; Reads: text, image, PDFs | Powers Pro reasoning in ChatGPT; Best for: hard reasoning; Reads up to 1,050,000 tokens at once; Reads: text, image, PDFs |
| Where it runs | ChatGPT Plus/Pro | ChatGPT Plus/Pro |
| Status | Current | Current |
| Sources | chatgpt.com · models.dev | chatgpt.com · models.dev |
Related pages
- Alternatives to GPT-6.1 Sol
- Claude Opus 5.5 vs GPT-6.1 Sol
- GPT-6.1 Sol vs Gemini 4 Argon
- Grok 4.7 vs GPT-6.1 Sol
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Questions people ask
What replaces o3?
OpenAI names GPT-5.6 Sol. o3 shuts down in OpenAI's developer service on Dec 11, 2026. OpenAI's newest main model in our directory is GPT-6.1 Sol.
What should I do if I used o3?
Developers: move off o3 before Dec 11, 2026.
Facts come from the companies' own pages, linked above, and were last checked Oct 28, 2026. Prices are US and can change. Picks are Hector's: no paid picks, sponsors always labeled, and no sponsorship from AI labs. Our policy.