GPT-6.1 Sol Not Showing in ChatGPT or Codex? Where It Actually Is, and the ‘Not Supported’ Error Fix (2026)

OpenAI launched GPT-6.1 Sol at DevDay on September 29, 2026. The pitch was simple: close to GPT-6 Astra on coding and agent work, at about a fifth of the token price.

Then a lot of paying users opened ChatGPT, clicked the model menu, and saw nothing new.

That’s not a glitch on your account. It’s where OpenAI put the model. Below is where it actually shows up, why it might still be missing, and what to try for each case.

In This Fix-It List

• Where Is GPT-6.1 Sol Available Right Now?
• Why Isn’t GPT-6.1 Sol in My ChatGPT Model Picker?
• Why Does Codex Say the Model Is “Not Supported” With a ChatGPT Account?
• Missing Only in the VS Code Extension?
• Is GPT-6.1 Sol Worth Switching To From GPT-6 Astra?
• Tips
• Warnings
• FAQ
• Sources

Where Is GPT-6.1 Sol Available Right Now?

As of October 2026, GPT-6.1 Sol is available in Codex (desktop app and CLI) and in ChatGPT Work on web and mobile for Plus, Pro, Business, Enterprise, and Edu plans, plus the OpenAI API as gpt-6.1-sol, but it is not available in regular ChatGPT chat, according to OpenAI’s ChatGPT Learn models page.

When I checked that page line by line, I found that it’s blunt about the split: GPT-6.1 Sol, GPT-6 Sol, and GPT-6 Luna “are available in Work and Codex. They aren’t available in Chat.”

Table: availability compiled from OpenAI’s ChatGPT Learn models page and open Codex GitHub issues #49464 and #49703, as of October 2, 2026.

So the first fix is often just looking in the right place.

Why Isn’t GPT-6.1 Sol in My ChatGPT Model Picker?

GPT-6.1 Sol is missing from the regular ChatGPT model picker because OpenAI launched it only in ChatGPT Work and Codex; switching to ChatGPT Work and using the model control under the composer is how a Plus or Pro user reaches it in ChatGPT.

Go through these in order:

1. Check your plan. Free and Go plans are excluded at launch. Settings will show your plan name.
2. Switch to ChatGPT Work. It’s a separate surface from Chat. Its model and reasoning control sits beneath the composer.
3. Look under the preset, not just the list. OpenAI’s page describes Power presets (Smarter, Faster) and an Advanced control for picking a specific model. If you only see presets, open Advanced.
4. On Enterprise or Edu, ask your admin. OpenAI says those plans keep GPT-6.1 Sol off by default until an administrator enables it.
5. Update the app. An old desktop or mobile build may not list the new model yet.

Most people stop at step 1, see a paid plan, and assume something’s broken. It’s usually step 2.

Why Does Codex Say the Model Is “Not Supported” With a ChatGPT Account?

The Codex CLI error “The ‘gpt-6.1-sol’ model is not supported when using Codex with a ChatGPT account” (HTTP 400) is an open bug reported on September 30, 2026 against Codex CLI 0.159.2 on macOS, where the model was missing from /model and rejected when called directly, according to Codex GitHub issue #49703.

This one is frustrating because your plan is fine.

The same thread links a similar report on Windows, and one commenter said the model worked on their own standalone 0.159.2 CLI. So it doesn’t hit everyone.

What to try:

• Update Codex CLI to the newest release and run /model again.
• Sign out and back in so the CLI refreshes your account’s model list.
• Try the Codex desktop app with the same account. Reporters in issue #49464 said the model worked there.
• Use an API key instead if you need it today. API access bills per token, separately from your ChatGPT plan.

I noticed that neither issue had a maintainer reply or a fix version when I checked them on October 2, 2026. Keep an eye on the thread rather than reinstalling over and over.

Missing Only in the VS Code Extension?

If GPT-6.1 Sol shows up in the Codex app and CLI but not in the Codex VS Code extension, the likely cause is the older Codex binary bundled inside the extension, as described in Codex GitHub issue #49464.

In that report, the extension’s bundled binary was version 0.155.0-alpha.16.3, while the standalone CLI on the same machine was 0.159.2. The reporter was on a Remote SSH connection to Windows with a ChatGPT Pro account.

Until the extension ships a newer binary, the practical workaround is to run the standalone CLI in VS Code’s integrated terminal. You keep your editor. You just pick the model with codex -m gpt-6.1-sol instead of the extension’s picker.

Is GPT-6.1 Sol Worth Switching To From GPT-6 Astra?

For most coding and agent work, yes: GPT-6.1 Sol costs $2 per million input tokens and $10 per million output tokens in the API, about one fifth of GPT-6 Astra’s standard price, and OpenAI says it matches Astra on the DeepSWE coding benchmark, according to The Next Web’s DevDay report on September 29, 2026.

When I compared the reported benchmark gaps, the trade-off looked narrow:

• Coding (DeepSWE v1.1): reported as matching Astra.
• Computer use (OSWorld 2.0): about 2.1 points behind Astra.
• Terminal-Bench Science: about $5.47 per task versus $23.80 for Astra, per The Next Web.
• Cached input: $0.10 per million tokens, 95% below the standard input rate.

Keep Astra for the jobs where that last couple of points matters, like long computer-use runs that fail expensively. Use Sol for the bulk of everyday work.

One thing to clear up: GPT-6.1 Sol is not the shelved GPT-6.1 Astra. OpenAI cancelled the October launch of GPT-6.1 Astra after safety testing, and GPT-6 Astra remains available. Sol is a separate, cheaper model that did ship.

Tips

• In the Codex CLI, check what you’re actually running with /model before a long task.
• Start with the default Power setting in ChatGPT Work and move to Smarter only for hard problems. It saves usage.
• If you use the API, structure prompts so the long system part repeats exactly. That’s what makes the $0.10 cached rate kick in.
• Bookmark issue #49703 rather than searching for fixes daily. It’ll show the fix version when one lands.

Warnings

• Don’t install unofficial “unlock” extensions that promise GPT-6.1 Sol in regular chat. OpenAI hasn’t released it there.
• API usage is billed separately from Plus or Pro. Switching Codex to an API key can create a bill you didn’t expect.
• Benchmark figures above come from OpenAI’s launch claims as reported by The Next Web, not independent tests.

FAQ

Can free ChatGPT users use GPT-6.1 Sol?

No. At launch, GPT-6.1 Sol is limited to Plus, Pro, Business, Enterprise, and Edu plans in ChatGPT Work and Codex. Free and Go plans are excluded.

When will GPT-6.1 Sol come to regular ChatGPT chat?

OpenAI has not given a date. Its models page says GPT-6.1 Sol is available in Work and Codex and not in Chat as of early October 2026.

Is GPT-6.1 Sol the same as GPT-6 Sol?

No. GPT-6 Sol is the earlier model. GPT-6.1 Sol launched on September 29, 2026 and scores higher on the reported coding and computer-use benchmarks.

Sources

• OpenAI ChatGPT Learn — Models
• The Next Web — OpenAI releases GPT-6.1 Sol at a fifth of GPT-6 Astra’s token price
• OpenAI Codex on GitHub — Issue #49703
• OpenAI Codex on GitHub — Issue #49464

Fact-checked against OpenAI’s ChatGPT Learn models page, The Next Web’s DevDay 2026 coverage, and open Codex GitHub issues #49464 and #49703 as of October 2, 2026. Availability and pricing can change quickly after a launch.