GitHub Copilot vs OpenAI Codex (2026)

Upgraded from P: six invocation surfaces plus scheduled tasks, GitHub Action, non-interactive exec mode, and third party triggers from Slack, Linear, GitHub and GitLab. The June basis predated most of this.

Upgraded from P: custom agents are a first class enterprise managed object with their own permissions, and Agent HQ orchestrates third party agents alongside Copilot's own. Sessions persist and are resumable, and the CLI documents memory across sessions.

Upgraded from P: a named Memories customization surface plus Computer History, alongside persistent projects, resumable sessions, compaction and AGENTS.md. The June basis predated the Memories feature.

Held at F, and the limit is worth stating: GitHub is explicit that the audit log does not include client session data, so prompts sent locally are not captured and a custom hook is needed to log CLI events. What is retained is agent session and administrative activity, which is the axis, but this is not a full reasoning trace. Same standard applied as cursor, which also held at F on a documented audit surface rather than live progress.

Upgraded from P. OpenTelemetry export with a documented event catalogue covering tool decisions, tool results and approval outcomes, plus a separate Compliance API and audit events surface and an Analytics API, is a retained per action record rather than usage reporting. Same standard applied to cursor and github-copilot, both of which held at F on documented audit surfaces. Recorded honestly: telemetry is opt in and off by default, and prompt content is redacted unless explicitly enabled.

Upgraded from P: local execution on the developer's own machine under an OS enforced sandbox, dev container support, Amazon Bedrock as a model provider path, and Private Link, IP allowlisting and mutual TLS for enterprise network control. Recorded honestly: cloud tasks run in OpenAI managed containers with no customer VPC or self hosted cloud option documented.

Upgraded from P: skills and plugins are both first class installable surfaces with build guides, enterprise plugin management and skill controls, and Codex accepts Claude Code plugin layouts. That is a distribution surface, which is the axis.

Corrected from N. The prior basis read OpenAI-only model, which describes the provider rather than the axis, the same error I corrected on anthropic-claude-code and google-jules. The model is selectable per session in config.toml, a Models page documents the choices, workspace model availability is an admin control, and Amazon Bedrock is documented as a deployment and model provider path. Held at P not F because all models are OpenAI's with no third party or BYOK option, narrower than activepieces or cline.

Downgraded from F per the lane wide axis rule, now applied to seven vendors here. Agentic code review, self diff review, test running and security scanning all verify the customer's code and the agent's own output. Usage and code generation dashboards measure adoption and volume, not agent correctness. No harness for evaluating or regression testing agent behaviour is documented.

Downgraded from F, ninth application of the lane wide axis rule. Code review, the Security plugin and CI scanning all act on the customer's code. The closest thing to agent evaluation is Auto-review, which judges individual agent actions against a risk policy at runtime, but that is a runtime guardrail already credited on HITL and not a harness for testing agent behaviour. Note the platform's Evals product is an API surface for the customer's own applications, not a harness for evaluating Codex itself, so it does not count here; the same fact should not do work on two records.

Confirmed at N on re retrieval rather than left on an unevidenced basis. The cloud agent runs in an ephemeral GitHub Actions environment reachable by network under firewall allowlist controls, and screenshot to code reads an uploaded image, but neither is the agent driving a browser or operating software through a human interface. Contrast cline and Claude Code in this lane, both of which document a browser tool.

Corrected from N. Browser and Computer use are listed as documented Capabilities in Codex's own navigation with dedicated pages, alongside a browser extension and Appshots, and the security page names browser and Computer Use activity as a distinct traffic surface requiring its own feature controls. The June basis missed this entirely.