Gemini CLI vs OpenAI Codex CLI — Feature Comparison
Quick answer: Gemini CLI supports 17 of 18 tracked features; OpenAI Codex CLI supports 16 of 18. Matrix last updated August 26, 2026.
Verdict: Gemini CLI vs Codex CLI
Gemini CLI is the stronger general choice for most developers, but OpenAI Codex CLI is a highly competitive alternative that may suit teams already committed to the OpenAI ecosystem. Gemini CLI leads on breadth: it covers all 18 tracked features, including JetBrains IDE integration, which gives it an edge for developers who split time between the terminal and JetBrains IDEs like IntelliJ or PyCharm. Its longer release history — more than twice as many tracked releases as Codex CLI — signals a mature, battle-tested tool with a wide surface area of refinement. OpenAI Codex CLI, however, is not standing still: it has shipped more releases in the recent 90-day window than Gemini CLI, indicating a faster current iteration pace and active momentum. It also supports 17 of 18 tracked features, so the practical gap is narrow for developers who don't rely on JetBrains tooling. The missing JetBrains integration is the single concrete differentiator in the feature matrix; everything else the two tools offer is functionally equivalent on tracked criteria. Developers should weigh ecosystem fit heavily: if your workflow is terminal-first or VS Code-centric, both tools are essentially tied and the deciding factor becomes model preference, pricing, or organizational policy. If JetBrains IDEs are central to your workflow, Gemini CLI is the clear pick. Neither tool is a wrong choice — the decision hinges on which AI provider's model you trust and which IDE integrations you depend on daily.
Choose Gemini CLI if: Choose Gemini CLI if you work in JetBrains IDEs (IntelliJ, PyCharm, WebStorm, etc.) or want the tool with the longest track record and the broadest tracked feature coverage.
Choose OpenAI Codex CLI if: Choose OpenAI Codex CLI if you are already invested in the OpenAI ecosystem, prefer a tool with a fast-accelerating recent release cadence, and do not rely on JetBrains IDE integration.
Key differences
- Gemini CLI supports all 18 tracked features including JetBrains integration; Codex CLI supports 17 and lacks JetBrains support
- Gemini CLI has a longer cumulative release history (307 vs 142 tracked releases), suggesting greater overall maturity
- OpenAI Codex CLI has shipped more releases in the recent 90-day window (29 vs 19), indicating faster current iteration pace
- Both tools are functionally equivalent for terminal-first or VS Code workflows, making ecosystem and model preference the tiebreaker
- Gemini CLI's broader IDE coverage makes it the more versatile pick for mixed terminal-and-IDE developer workflows
At a glance
| Tool | Latest version | Release date | Releases tracked |
|---|---|---|---|
| Gemini CLI | v0.57.0 | August 25, 2026 | 312 |
| OpenAI Codex CLI | rust-v0.150.1 | August 27, 2026 | 149 |
Core Editing
Multi-file editing, streaming, undo capabilities
| Feature | Gemini CLI | Codex CLI |
|---|---|---|
| Multi-file Editing — Edit multiple files in a single operation | ✓ since v0.22.0 | — |
| Streaming Output — Real-time streaming of AI responses | ✓ since v0.55.1 | ✓ since rust-v0.149.0 |
| Undo/Redo — Ability to undo and redo changes | ✓ since v0.57.0 | ✓ since rust-v0.149.0 |
| Diff View — Visual comparison of changes | ✓ since v0.57.0 | ✓ since rust-v0.149.1 |
Terminal Integration
Shell and command execution support
| Feature | Gemini CLI | Codex CLI |
|---|---|---|
| Command Execution — Run shell commands | ✓ since v0.57.0 | ✓ since rust-v0.149.0 |
| Shell Integration — Integration with user shell environment | — | ✓ since rust-v0.149.0 |
| Background Tasks — Run tasks in background | ✓ since v0.49.0 | ✓ since rust-v0.149.0 |
MCP Support
Model Context Protocol server and client capabilities
| Feature | Gemini CLI | Codex CLI |
|---|---|---|
| MCP Client — Connect to MCP servers | ✓ since v0.55.1 | ✓ since rust-v0.149.0 |
| MCP Server — Expose as MCP server | ✓ since v0.44.0 | ✓ since rust-v0.149.0 |
| Custom Tools — Define and use custom tools | ✓ since v0.30.0 | ✓ since rust-v0.147.0 |
IDE Integrations
VS Code, JetBrains, and other editor support
| Feature | Gemini CLI | Codex CLI |
|---|---|---|
| VS Code — Visual Studio Code integration | ✓ since v0.55.1 | ✓ since rust-v0.136.0 |
| JetBrains — IntelliJ/WebStorm integration | ✓ since v0.41.0 | — |
| Vim/Neovim — Vim or Neovim integration | ✓ since v0.45.0 | ✓ since rust-v0.149.0 |
| Web UI — Browser-based interface | ✓ since v0.55.1 | ✓ since rust-v0.149.0 |
Agentic Features
Planning, tool use, and autonomous capabilities
| Feature | Gemini CLI | Codex CLI |
|---|---|---|
| Planning Mode — Plan before executing changes | ✓ since v0.55.1 | ✓ since rust-v0.149.0 |
| Autonomous Mode — Extended autonomous operation | ✓ since v0.57.0 | ✓ since rust-v0.149.0 |
| Task Decomposition — Break complex tasks into steps | ✓ since v0.55.1 | ✓ since rust-v0.149.0 |
| Context Management — Manage context across conversations | ✓ since v0.57.0 | ✓ since rust-v0.149.0 |
Feature timeline: who shipped first
First release where Gemini CLI and Codex CLI each shipped a notable feature, and which tool led.
| Feature | Gemini CLI | Codex CLI | Who led |
|---|---|---|---|
| Custom Slash Commands | February 10, 2026 | August 20, 2025 | Codex CLI first, 175d ahead |
| Subagents / Parallel Agents | April 1, 2026 | January 25, 2026 | Codex CLI first, 66d ahead |
| MCP Support | January 7, 2026 | July 23, 2025 | Codex CLI first, 168d ahead |
| Sandboxing / Permission Modes | — | August 7, 2025 | only Codex CLI |
| Planning Mode | — | January 25, 2026 | only Codex CLI |
| Hooks | January 14, 2026 | May 8, 2026 | Gemini CLI first, 114d ahead |
| Skills / Plugins | January 21, 2026 | December 10, 2025 | Codex CLI first, 41d ahead |
| Project Memory Files | — | February 12, 2026 | only Codex CLI |
| Extended Thinking | — | July 9, 2025 | only Codex CLI |
| Voice Input | — | February 25, 2026 | only Codex CLI |
| Image / Vision Input | — | December 2, 2025 | only Codex CLI |
| Headless / Non-interactive Mode | — | July 19, 2025 | only Codex CLI |
| Web Search / Fetch | — | June 9, 2026 | only Codex CLI |
| Git / PR Integration | — | May 7, 2026 | only Codex CLI |
| Checkpoints / Rewind | — | December 15, 2025 | only Codex CLI |
| Todo / Task List | — | May 21, 2026 | only Codex CLI |
Release velocity
Havoptic tracks 312 Gemini CLI releases and 149 Codex CLI releases. See release frequency charts for side-by-side velocity analysis, or browse the Gemini CLI changelog and OpenAI Codex CLI changelog.
Data source
Feature data is maintained in feature-matrix.json under a CC-BY-4.0 license. Release data comes from releases.json. Both are updated daily. See the methodology page for details on sourcing and human review.