Side by side

As verified on November 5, 2026.

Feature map

The open-source column describes OpenCode, which Part III covers beside Claude Code and Codex. "Not documented" means the feature was not found in the product's documentation, not that it is impossible.

What they now share

The two apps have converged. Both are now AI Worker platforms. Both have moved from answering questions to doing whole jobs: research, files, a browser, your computer, your connected apps, and finished documents, spreadsheets and presentations at the end. Both build presentations you can edit yourself and export to PowerPoint or Google Slides (ChatGPT's Slides is reported and still rolling out). Both draw charts and interactive visuals inside the conversation. Both let you save a way of working as a skill. Both keep a separate, specialist place for software. Both run work in the cloud so it continues with your laptop closed, and let you follow it from your phone. Both run work on a schedule. Both connect to outside tools through MCP, which is why a connector you build in Part III can serve both, and OpenCode too. And both vendors now give the same advice for briefing them: the outcome and how to check it, not the steps.

Where they differ

The two rows differ in the middle box, who decides that work begins. They end in the same place: a permission setting that decides what the worker may do once it starts. That is why this section begins with permissions.

How permission is set. This is the difference that matters most for an AI Worker. Claude sets one level, Auto or Manual, for a whole conversation, and the Code tab adds finer modes. ChatGPT sets a permission mode with a sandbox around the workspace, can route approvals to a reviewing model, and in the cloud browser separates permission to visit a site from permission to act on it. Before you delegate, read what each mode actually allows, not its name.

Who decides that work begins. In Claude, the conversation decides. In ChatGPT, you do, by choosing Work. This difference is narrowing (reported), so do not choose an app on it.¹,² Whichever app you use, the permission setting is where you control what happens once work begins.

What surrounds the coding agent. Claude's Code tab has grown into a workspace for running many sessions at once: nested sessions, a coordinating session and projects with cloud threads. Codex leans toward the software lifecycle: inline diffs, pull-request review, several repositories, worktrees and cloud runs.

What starts work without you. ChatGPT can start a task when an email, a Slack message or a pull request arrives. Claude's cloud tasks start on a schedule, a GitHub event or an API call.

What you can build on top. Claude's artifacts can call Claude for whoever uses them, at the user's cost. ChatGPT's Sites publish web apps that update from their data. Claude also lets you reshape the app itself with mods.

Where open source fits. OpenCode is a coding agent, not a desktop app for everyday delegated work. Its strength is choice: it runs models from many providers, including models on your own computer, which matters where cost, data location or vendor independence comes first. For a non-developer starting out, the two vendor apps remain the easier place to begin.

What the comparison cannot tell you

Neither vendor's documentation shows which app reasons better, makes fewer spreadsheet errors, finishes more web tasks, or keeps your data safer. An easier interface can reduce friction, but it cannot stand in for a correct result or a sound permission boundary. The only fair comparison is the one this book teaches you to run: the same job, the same inputs, the same done-when and the same limits on each, repeated, with the results checked against the files each run left behind, never against the worker's account of its own work.