The Codex Chrome extension, explained
The Codex Chrome extension is OpenAI's plugin for the ChatGPT desktop app. What it does, who gets it, why it often goes missing, and a read-only alternative.
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“Codex Chrome extension” turns up two different things. One is OpenAI’s own extension, which lets Codex use a browser you are already signed in to. The other is the crowd of sidebar extensions that park a GPT model beside your page. This guide covers the official one first, including why so many people install it and then cannot find it.
What the Codex Chrome extension is
OpenAI shipped it on 7 May 2026 as Codex for Chrome. It is a bridge rather than a chat sidebar. The extension sits in the browser, the model sits in OpenAI’s desktop app, and the app borrows your browser for sites you are logged in to. At launch OpenAI said it “lets Codex use Chrome for browser tasks that need your signed-in browser state.”
The name has drifted since, which is most of the confusion. The Web Store listing at that extension ID now reads “ChatGPT”, published by OpenAI, with four million users and a 5 September 2026 update. OpenAI’s docs call it the ChatGPT browser extension, and the app lists it under Computer Use. Codex merged into the ChatGPT desktop app on 9 July 2026, so the Codex-branded install from May and the ChatGPT-branded one today are the same extension.
Who can use it
- The desktop app is required. OpenAI’s setup starts with updating the ChatGPT desktop app. The extension does nothing alone.
- Five browsers, not one. The docs list Chrome, Edge, Brave, Opera and Vivaldi, with side chat in all of them except Opera.
- macOS and Windows. MacRumors quoted OpenAI describing it on “Macs and PCs” on launch day.
- Plans. ChatGPT’s pricing page marks Computer Use and the Chrome extension as limited on Free, with regional limits.
- Region matters. The EU and the UK trailed the first rollout, which coverage put down to regulatory review.
How to install the Chrome extension for Codex
OpenAI documents six steps. Skipping one is why the connection never completes.
- Update the ChatGPT desktop app.
- Open Settings > Computer Use in the app.
- Select your browser and follow any prompt to install the required plugin.
- Select Install beside the browser, add the extension, and review the permission prompts.
- Return to Computer Use and confirm the browser shows Manage.
- Start a ChatGPT Work or Codex chat and select your browser with an
@-mention.
The permissions are wide. The listing asks for the page debugger, your data on all websites, your browsing history, and your bookmarks and downloads. Read it rather than clicking past it.
Why the Codex Chrome extension says it is not available
This is the question most people arrive with. The extension is gated more often than broken.
OpenAI’s support account said as much in the developer forum on 13 May 2026. “Codex for Chrome seems to depend on gradual rollout plus account/region eligibility, so it may not show up for everyone yet.”
Community reports split the failure in two. On the store side, an open GitHub issue from 8 May 2026 describes the listing refusing to install, and those reports cluster in Europe and the UK. On the app side, several issues describe the Chrome plugin vanishing from the Codex plugin directory after an update, traced to a stale marketplace cache.
These are the fixes users report. Sign out and back in, restart the desktop app, install from the Web Store listing instead of the in-app button, and check your Chrome profile. Treat them as reports, because OpenAI has not published a fix.
What Codex can do in your browser
The payoff is that it works on pages behind your login, with no API connector. OpenAI’s line at launch was that Codex “can use the browser to test web apps, get context across multiple tabs, use web DevTools, and more without taking over the browser from the user.” Coverage of the launch adds filling forms, reviewing dashboards and multi-tab research, with work landing in task-specific tab groups.
The documented gaps matter too. OpenAI’s docs point localhost at the built-in browser rather than the Chrome extension. File uploads need “Allow access to file URLs” turned on in Chrome, and the docs say history access is scoped to the request, with no always-allow option.
Read this before you turn the extension on
An agent that reads pages can be steered by pages. Hidden text on a site or inside an email can carry instructions the model treats as yours, and an agent working through your browser has your logged-in sessions. OpenAI does not dress this up. Its guidance is to “treat page content as untrusted context, and review the website before allowing ChatGPT to continue.”
The guardrails are permission-shaped. By default it asks before touching a new site, and you answer with allow once, allow for this site, allow for all sites, or decline, backed by an allowlist and a blocklist. OpenAI labels “allow for all sites” elevated risk because it switches the confirmations off, and says browser history “can include sensitive telemetry, internal URLs, search terms, and activity from browser sessions on signed-in devices.”
Start on low-stakes sites, watch the first runs, and keep it away from banking.
If you want GPT models while you browse, without the agent
Plenty of people searching for this extension do not want delegation. They want to read a page and ask a model about it, or summarize something long.
That is the job our extension, UtilEngine, does. Press your shortcut on any page for Ask AI and Chat, with the page you are on as context. Access is bring your own key through a single OpenRouter key, billed per token at the provider’s own prices with nothing added by us. The model list runs to 77 entries, 30 of them from OpenAI, switchable per conversation alongside Claude and Gemini. Its AI tools are read only and show as chips in the answer, so it reads the page and searches the web, your tabs, your history and your bookmarks. It never clicks, types or fills a form, and it runs in Chrome, Brave and Edge.
The caveats run both ways. UtilEngine costs $49 once plus your token spend, there is no free tier, and it will not do your web chores. If you want an agent inside your logged-in accounts, OpenAI’s extension is the real thing. The same split shows up with Claude in Chrome and with OpenAI’s ChatGPT extension.
Common questions
Is the Codex Chrome extension free?
Installing it costs nothing, but it is half the product. ChatGPT’s pricing page marks Computer Use and the Chrome extension as limited on Free, with regional limits, so real use tracks a paid plan.
Does the Codex Chrome extension work on Windows?
Yes. Launch coverage on 7 May 2026 quoted OpenAI describing it on “Macs and PCs”. Separate GitHub issues do report the Chrome plugin missing or failing to install on Windows, but those name the Codex plugin directory, not the extension.
Does it work in Brave or Edge?
Both, now. OpenAI’s docs list Chrome, Edge, Brave, Opera and Vivaldi, with side chat everywhere except Opera. At launch Chrome was the only option.
Is it the same as the ChatGPT extension?
Now, yes. The listing at the Codex extension ID is titled “ChatGPT” and published by OpenAI. Codex merged into the ChatGPT desktop app in July 2026 and the two installs converged.
Do I need the Codex app installed?
Yes. Setup starts with updating the ChatGPT desktop app, which is where Codex now lives. The browser shows as connected only after the app pairs with it.