AI Coding Agent Comparison · 2026

Claude Code vs Codex CLI

Claude Code (CLI / terminal agent, $20/mo (Pro) incl. Claude Code) vs Codex CLI (CLI / terminal agent, Included with ChatGPT plans): pricing, models, open-source status, benchmarks, and best use cases. See which AI coding agent is right for your workflow.

Claude Code

Anthropic · CLI / terminal agent
proprietary
$20/mo (Pro) incl. Claude Code

Codex CLI

OpenAI · CLI / terminal agent
open source
Included with ChatGPT plans
ComparisonClaude CodeCodex CLI
CategoryCLI / terminal agentCLI / terminal agent
TypeTerminal agentTerminal agent
VendorAnthropicOpenAI
Pricing$20/mo (Pro) incl. Claude CodeIncluded with ChatGPT plans
Open sourceNoYes
ModelsClaude Opus 4.8, Claude Sonnet 5, Claude Haiku 4.5GPT-5.5, GPT-5.3 Codex, o-series reasoning
BenchmarksSWE-bench Verified: 88.6% · Terminal-Bench: 74.6%Terminal-Bench: 82.7%
Best forDeep reasoning, complex multi-file refactors, debugging across large codebasesOpenAI ecosystem users, parallel task execution, open-source terminal workflows

Claude Code is proprietary and best for deep reasoning, complex multi-file refactors, debugging across large codebases. Anthropic's terminal-native coding agent. Runs in your terminal, reads your codebase, executes commands, writes and runs tests, and handles multi-file edits. With Opus 4.8 it posts 88.6% on SWE-bench Verified — the highest published score in Anthropic's Opus 4.8 table.

Codex CLI is open source and best for openai ecosystem users, parallel task execution, open-source terminal workflows. OpenAI's open-source terminal coding agent. Supports parallel tasks and routes to GPT-5.5 and Codex models. Included with ChatGPT subscriptions; can also run on API keys.

Both tools are part of the 2026 AI coding agent landscape. The right choice depends on whether you need a CLI / terminal agent or a CLI / terminal agent, your budget, and which models you prefer. See the full list of coding agents on our coding agents page to compare more options.