GILD verdict
Choose Codex if engineers need the agent in the editor, the ChatGPT apps, and the cloud, or if you hold no Code Assist subscription.
Choose Gemini CLI if engineers work in the terminal and CI and an existing Code Assist subscription or Vertex AI billing already pays for it. On Terminal-Bench 4.0, Codex with GPT-6 Astra solved 58.18% of tasks, and Gemini CLI has no listed run. Google points Gemini buyers to Antigravity CLI through Gemini Enterprise, so test it on the same tasks before choosing Gemini CLI.
Codex wins for any team buying new, because ChatGPT plans include it and Google stopped selling new Code Assist subscriptions on October 9, 2026. Gemini CLI stays in the terminal and CI and runs on existing Code Assist subscriptions or Gemini API and Vertex AI billing. Both are open-source terminal agents that edit code and run commands and MCP tools.
Choosing between Gemini CLI and Codex
Choose Gemini CLI if
- Your organization holds an existing Gemini Code Assist Standard or Enterprise subscription, or bills Gemini through Vertex AI or a paid API key.
- You want the full CLI source under Apache 2.0 and a system settings file that overrides user settings on every machine.
- You want pull request review and issue triage from a GitHub Action you configure in your own workflows.
Choose Codex if
- Codex comes inside ChatGPT Business at US$20 per user per month billed annually, while Google sells no new Code Assist subscriptions.
- Engineers want an IDE extension, ChatGPT apps, and cloud tasks as well as the CLI.
- Individual engineers need a personal plan: ChatGPT Free and Plus include Codex, while Gemini CLI no longer serves Google AI Pro or Ultra.
Side by side
| Dimension | Gemini CLI | Codex |
|---|---|---|
| Where it runs | Terminal CLI, headless scripts, the run-gemini-cli GitHub Action, and Cloud Shell; it also powers Gemini Code Assist agent mode in VS Code | ChatGPT desktop, web, and mobile apps, a CLI, an IDE extension, and Codex Cloud |
| Individual priceList prices in US dollars. Included usage differs by plan and is not directly comparable. | No individual subscription since June 18, 2026; a paid Gemini API key is billed per token | Included in ChatGPT Plus: US$20 per month |
| Team price | No new subscriptions since October 9, 2026; existing Gemini Code Assist Standard contracts: US$22.80 per user per month on a monthly commitment, or US$19 on a 12-month commitment | Included in ChatGPT Business: US$25 per user per month billed monthly, or US$20 billed annually (2+ users) |
| Beyond the plan | 1,500 (Standard) or 2,000 (Enterprise) model requests per user per day; past that, a Gemini API key or Vertex AI at per-token rates | Additional credits on Plus, Pro, and Business; usage with an API key is billed at API pricing |
| Permissions | Prompts before tool calls by default; YOLO mode only by command-line flag, and administrators can disable it; sandboxing is off unless configured | Sandbox modes from read-only to workspace-write (the default) to danger-full-access, with an on-request or never approval policy |
| Project instructions | GEMINI.md files loaded from the project hierarchy; context.fileName can add AGENTS.md | AGENTS.md, read once per run before work starts |
| MCP | Stdio, SSE, and Streamable HTTP servers; mcp.allowed restricts which servers connect | STDIO and Streamable HTTP servers, configured in config.toml |
| Open source | The CLI, under Apache 2.0 | The CLI and SDK; the IDE extension and Codex Cloud are not open source |
| Pull request review | run-gemini-cli GitHub Action, on new pull requests or an @gemini-cli /review comment | Codex code review on GitHub, requested with @codex review or set to run automatically |
| Terminal-Bench 4.0Terminal-Bench 4.0 is the terminal-task leaderboard that Stanford and the Laude Institute host. Its best Gemini entry, Gemini 3.8 Flash in the mini-SWE-agent harness, solved 19.09%. | No Gemini CLI run listed as of October 25, 202622 | 58.18% of tasks solved with GPT-6 Astra, submitted September 3, 202622 |
What practitioners report, side by side
Each product's figures come from its own practitioners, for the group you pick.
Overall signal
All practitioners rate Codex +44, 47 points above Gemini CLI at −3. Most of the gap is in praise, with 59 of Codex's 106 sources positive against 20 of Gemini CLI's 64. Codex has 12 negative and Gemini CLI 22.
The score counts the authors from all practitioners that take a side, one vote each with their latest view, and is how far positive votes lead negative ones, per 100 votes, so Gemini CLI's −3 rests on votes split 20 positive, 20 mixed and 22 negative and Codex's +44 on 55, 30 and 12.
A lead of a fifth of the votes reads positive and a lead of half strong positive, with the same lines below zero. The dots show each source, positive, mixed, negative. Use a task pilot to measure accepted work and review time.
Footprint on the Agentic Software Development stack
They differ on two of 12 layers. On Codebase context, Gemini CLI supports it and Codex is core. On CI/CD, Gemini CLI supports it and Codex touches it. Coverage is each product's placement on this stack, as its product page shows it. Core is a job the product owns; Supports and Touches are jobs it helps with. Coverage says nothing about how well a product does them.
| Layer | Gemini CLI | Codex |
|---|---|---|
| Build | ||
| Codebase context | Supports | Core |
| Ship | ||
| CI/CD | Supports | Touches |
The 10 layers where they match
| Layer | Gemini CLI | Codex |
|---|---|---|
| Plan | ||
| Work planning | Supports | Supports |
| Build | ||
| Coding | Core | Core |
| Agent runtime | Core | Core |
| Tool execution | Core | Core |
| Validate | ||
| Debugging | Supports | Supports |
| Testing | Supports | Supports |
| Code review | Supports | Supports |
| Application security | Touches | Touches |
| Ship | ||
| Source control | Touches | Touches |
| Operate | ||
| Observability | Touches | Touches |
What practitioners praise
Among all practitioners, Codex alone has six praise themes that reach 5 sources from 3 authors. Code Quality and Pull Request Review lead, at 27 of 33 and 12 of 12. Of the two themes both carry, Developer Experience differs most. It is praised in 7 of the 20 Gemini CLI sources that discuss it, against 20 of 36 for Codex. Gemini CLI alone has four praise themes that reach 5 sources from 3 authors. Open Source & Extensibility and Large Context lead, at 11 of 11 and 10 of 10.
| Praised for | Gemini CLI | Codex |
|---|---|---|
| Multi-Step Execution | 9 of 11 | 12 of 17 |
| Developer Experience | 7 of 20 | 20 of 36 |
| Open Source & Extensibility | 11 of 11 | Not a theme in its sources |
| Large Context | 10 of 10 | Not a theme in its sources |
| Speed | 4 of 7 | Not a theme in its sources |
| Headless Automation | 3 of 7 | Not a theme in its sources |
| Code Quality | Not a theme in its sources | 27 of 33 |
| Pull Request Review | Not a theme in its sources | 12 of 12 |
| Value for Money | Not a theme in its sources | 11 of 15 |
| Codebase Understanding | Not a theme in its sources | 10 of 11 |
| Fast Runs | Not a theme in its sources | 6 of 12 |
| Stability | Not a theme in its sources | 1 of 6 |
Each count is the sources that praise a theme, or raise it as a concern, out of those that discuss it. A row pairs the two products when both carry a theme under the same or an equivalent name.
A count ending in "so far" has under 5 sources from 3 authors among all practitioners. "Not a theme in its sources" means GILD found no theme of that name in that product's sources.
What practitioners raise as concerns
Gemini CLI's sources raise Requires Strong Review more often than Codex's. It is raised in 7 of the 8 Gemini CLI sources that discuss it, against 9 of 23 for Codex. Gemini CLI alone has four concern themes that reach 5 sources from 3 authors. Reliability and Product Direction lead, at 25 of 27 and 14 of 16. Codex alone has four concern themes that reach 5 sources from 3 authors. Usage Limits / Cost and Inconsistent Results lead, at 22 of 39 and 15 of 16.
| Raised as a concern | Gemini CLI | Codex |
|---|---|---|
| Needs Close Steering | 7 of 7 | 6 of 9 |
| Requires Strong Review | 7 of 8 | 9 of 23 |
| Reliability | 25 of 27 | Not a theme in its sources |
| Product Direction | 14 of 16 | Not a theme in its sources |
| Quotas & Cost | 13 of 16 | Not a theme in its sources |
| Permissions & Safety | 7 of 8 | Not a theme in its sources |
| Usage Limits / Cost | Not a theme in its sources | 22 of 39 |
| Inconsistent Results | Not a theme in its sources | 15 of 16 |
| Speed | Not a theme in its sources | 13 of 22 |
| Communication & Steering | Not a theme in its sources | 7 of 12 |
22 sources
- Gemini Code Assist docs: Gemini Code Assist Standard and Enterprise subscriptions
- Gemini Code Assist release notes
- Google Developers Blog: Transitioning Gemini CLI to Antigravity CLI (May 19, 2026)
- Gemini CLI docs: Quota and pricing
- Gemini for Google Cloud pricing
- Gemini for Google Cloud: Quotas and limits
- Gemini Code Assist docs: Gemini CLI
- Gemini CLI docs: Installation
- Gemini CLI docs: Configuration reference
- Gemini CLI docs: Enterprise configuration
- Gemini CLI docs: Project context (GEMINI.md)
- Gemini CLI docs: MCP servers
- google-gemini/gemini-cli on GitHub
- google-github-actions/run-gemini-cli on GitHub
- Codex docs: Overview
- Codex docs: Pricing
- Codex docs: Sandboxing
- Codex docs: AGENTS.md
- Codex docs: GitHub code review
- Codex docs: MCP
- Codex docs: Open source
- Terminal-Bench 4.0 leaderboard, Stanford, Harbor, and Laude Institute (Oct 23, 2026)