WhichBot › What replaced it › What replaced GPT-5.5?
Last checked Oct 28, 2026 · plain English · no paid picks
What replaced GPT-5.5?
Short answer: In ChatGPT, GPT-6.1 Sol replaced GPT-5.5 on paid plans and GPT-6 Luna on Free and Go. GPT-5.5 left ChatGPT, ChatGPT Work and Codex on Oct 14, 2026. It's still available to developers.
What to do: Nothing, if you use the ChatGPT app: you were moved over. GitHub Copilot also removed it on Oct 19, 2026 and suggests GPT-6.1 Sol.
The facts
| Old | GPT-5.5 |
|---|---|
| Status | Replaced. Retired from ChatGPT, ChatGPT Work and Codex (ChatGPT sign-in) on Oct 14, 2026. Still available in the OpenAI developer service and in Codex with an developer service key. Also removed from GitHub Copilot on Oct 19, 2026 (GitHub suggests GPT-6.1 Sol) |
| Replaced by | GPT-6.1 Sol / GPT-6 Luna |
| Official source | help.openai.com · github.blog |
| Last checked | Oct 28, 2026 |
The replacement at a glance
| GPT-6.1 Sol | GPT-6 Luna | |
|---|---|---|
| What it is | OpenAI's main model on paid ChatGPT plans | OpenAI's low-cost model |
| Made by | OpenAI | OpenAI |
| Price | Developer price: $2 in and $10 out per million tokens | Developer price: $0.10 in and $0.50 out per million tokens |
| Good at | Reads up to 1,050,000 tokens at once; Reads: text, image, PDFs | Best for: cheap, light tasks; Reads up to 1,050,000 tokens at once; Reads: text, image, PDFs |
| Where it runs | ChatGPT Plus/Pro | ChatGPT Go |
| Status | Current | Current. Named replacement for GPT-4o / 4.1 family |
| Sources | chatgpt.com · models.dev | platform.openai.com · chatgpt.com · models.dev |
Related pages
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- Grok 4.7 vs GPT-6.1 Sol
- DeepSeek V4.1 Flash vs GPT-6 Luna
- What replaces GPT-4o?
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- What replaces o3?
- What replaced o4-mini?
- What replaces GPT-5.1?
Questions people ask
What replaced GPT-5.5?
In ChatGPT, GPT-6.1 Sol replaced GPT-5.5 on paid plans and GPT-6 Luna on Free and Go. GPT-5.5 left ChatGPT, ChatGPT Work and Codex on Oct 14, 2026. It's still available to developers.
What should I do if I used GPT-5.5?
Nothing, if you use the ChatGPT app: you were moved over. GitHub Copilot also removed it on Oct 19, 2026 and suggests GPT-6.1 Sol.
Does GPT-5.5 still work?
Replaced. Retired from ChatGPT, ChatGPT Work and Codex (ChatGPT sign-in) on Oct 14, 2026. Still available in the OpenAI developer service and in Codex with an developer service key. Also removed from GitHub Copilot on Oct 19, 2026 (GitHub suggests GPT-6.1 Sol)
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.