Criterion Claude Code OpenAI Codex
CategoryAI Coding AssistantsAI Coding Assistants
In one sentenceAnthropic's agentic coding tool that reads your codebase, edits files and runs commands from the terminal, IDE, desktop or browser.OpenAI's coding agent, included with ChatGPT plans and usable with an API key.
Problem it solvesMulti-step engineering tasks such as fixing bugs, writing tests or updating dependencies take many manual steps. Claude Code carries out those steps and reports back for review.Engineering backlogs contain many well-defined coding tasks. Codex takes those tasks on so developers can focus on review and design.
Free planNoYes
Developer APIYes — docsYes — docs
Open sourceNoNo
PlatformsmacOS, Windows, Linux/WSL, VS Code, JetBrains IDEs, Desktop app, Web, iOS/Android (via Claude app), SlackDesktop app, CLI, IDE extension, Web, iOS
Pricing (summary)Claude Code is included in Claude Pro ($20/month, or $17/month billed annually), Max (from $100/month), Team and Enterprise plans. It can also be used pay-as-you-go with an Anthropic API key at standard token rates.
Checked 2026-10-19		Codex is included in ChatGPT Free, Go ($8), Plus ($20), Pro (from $100), Business ($25 per user monthly or $20 annually) and Enterprise/Edu plans. Usage limits rise with the plan. API-key usage is billed separately at standard API token rates.
Checked 2026-10-19
Strengths
  • Many surfaces sharing one configuration
  • Strong extensibility (MCP, skills, hooks, SDK)
  • Choice of subscription or API billing
  • Bundled with ChatGPT subscriptions
  • Wide range of models and speed modes
  • Works with API key for local use
Limitations
  • Not included in the free Claude plan
  • Usage on subscriptions is limited per 5-hour session
  • Changes still need human review
  • Usage per 5-hour window is an estimate and varies by model and task
  • Cloud features not available with API key
  • Free and Go tiers are for light use