OpenAI's Codex and Anthropic's Claude Code are both coding agents — AI products that take a task description and do real work in your repo. Both run on top-tier models (GPT-5.2-Codex and Claude Sonnet 4.6 / Opus 4.7). Both can read, write, run code, and execute commands. The differences emerge in the design philosophy, the model under the hood, and the workflow each one optimizes for.
We use both at Respan and across our customer base. This is the side-by-side from running them in production.
TL;DR — when to pick each
| Pick Codex if... | Pick Claude Code if... |
|---|---|
| You want a tightly-integrated OpenAI experience | You want the strongest coding model under the hood |
| Your stack is OpenAI-first elsewhere | You want long-horizon autonomous runs |
| You want both API access and consumer agent in one product | You want pay-per-token pricing flexibility |
| You like the cloud-runs-the-agent model | You like the terminal-first, local-first model |
The honest answer: most engineers we see who try both end up preferring Claude Code for hard repo-wide tasks because Sonnet 4.6 / Opus 4.7 lead on coding evals. Codex is competitive and tightly integrated; Claude Code is the default when raw coding ability matters most.
What each is
Codex is OpenAI's coding agent product, which runs GPT-5.2-Codex (a model purpose-built for the coding agent loop). Codex ships through:
- The Codex web app — agent runs in OpenAI's cloud, you give it tasks
- Codex CLI — local terminal interface
- VS Code / Cursor integrations
GPT-5.2-Codex (the underlying model) is $1.75/$14 per 1M tokens, dedicated specifically to coding agent workloads.
Claude Code is Anthropic's terminal coding agent. Runs as a CLI (claude) you point at a repo. Models under the hood: Sonnet 4.6 (Pro tier) or Opus 4.7 (Max / Premium tier).
We covered Claude Code in detail in our Claude Code vs Cursor article. The summary: terminal-native, pay-as-you-go API or subscription billing, agent loop optimized for long autonomous runs.
Models
| Product | Model | Pricing | Context |
|---|---|---|---|
| Codex | GPT-5.2-Codex | $1.75 / $14 per 1M | 400k |
| Claude Code (Pro) | Claude Sonnet 4.6 | $3 / $15 per 1M | 1M |
| Claude Code (Max/Premium) | Claude Opus 4.7 | $5 / $25 per 1M | 1M |
GPT-5.2-Codex is purpose-built for agentic coding. Claude Code uses Anthropic's general-purpose models which happen to be best-in-class at coding. Different design philosophy, similar end-state.
Coding capability
Vendor-stated benchmarks (SWE-bench Verified, LiveCodeBench, multi-file edit rates) put Sonnet 4.6 / Opus 4.7 ahead of GPT-5.2-Codex on most public coding benchmarks. The Feb 2026 milestone where Sonnet 4.6 caught the previous-generation Opus on coding evals reflects how fast Anthropic has been pushing coding capability specifically.
In our blind production tests across multi-file refactors, the order is roughly:
- Claude Opus 4.7 (best on hard tasks)
- Claude Sonnet 4.6 (close second, 1.67× cheaper)
- GPT-5.2-Codex (competitive on simpler tasks, slightly behind on multi-file edits)
- GPT-5.5 (general flagship; can code well but Codex is more targeted)
The gap is smaller than a year ago. GPT-5.2-Codex is a real product. Anthropic just leads marginally in production coding agent reliability.
Workflow comparison
Codex workflow:
- You describe a task in the Codex web app or CLI
- The agent runs in OpenAI's cloud (or locally for CLI)
- Cloud runs are async — you can close the tab and come back
- Strong handoff/multi-agent patterns via the OpenAI Agents SDK underneath
Claude Code workflow:
- You run
claudein a terminal in your repo - The agent runs locally on your machine, reading and writing your files
- Synchronous in the terminal but you can leave it running
- Long autonomous runs are well-supported (the agent will work for an hour without supervision)
Cloud-based vs local-based is the most fundamental difference. Codex's cloud model is good for: long-running tasks where you want to context-switch away while the agent works, asynchronous workflows, less local resource use. Claude Code's local model is good for: privacy (no code leaves your machine), full filesystem access, easier integration with local toolchains.
Pricing
| Tier | Codex | Claude Code |
|---|---|---|
| Cheapest entry | ChatGPT Plus $20/mo (limited Codex usage) | Claude Pro $20/mo (limited Sonnet usage) |
| Mid-tier | ChatGPT Pro $200/mo | Claude Max $100/mo |
| Per-seat enterprise | Codex Enterprise $25-40/seat | Claude Premium $125/seat |
| Pay-as-you-go API | GPT-5.2-Codex $1.75/$14 | Anthropic API $3/$15 (Sonnet) or $5/$25 (Opus) |
Claude Code has lower mid-tier pricing ($100/mo Max vs $200/mo ChatGPT Pro) but higher API rates. Codex has higher mid-tier but lower API rates. The break-even point depends on whether you're a subscription user or pay-as-you-go.
Reliability and ecosystem
Codex:
- OpenAI Agents SDK underneath — production-grade execution semantics
- Tighter integration with the OpenAI consumer product surface
- VS Code / Cursor integrations are first-party
- Agent run history and replay in the Codex web UI
Claude Code:
- Battle-tested at agent reliability over long runs (lower lost-agent rate in our trace data)
- Terminal-first design means it works on any shell — laptops, servers, CI
- Less polished GUI for agent run history
CLAUDE.mdfor project context (simple, version-controlled)
For long-horizon autonomous runs (1+ hour), Claude Code has been our default. For tightly-integrated cloud-based agent workflows, Codex is competitive and improving fast.
Frank's take — when I actually pick which
Default to Claude Code for repo-wide hard tasks. Multi-file refactors, long autonomous runs, complex coding problems. The Sonnet 4.6 / Opus 4.7 quality lead matters most here.
Use Codex when the OpenAI ecosystem fit is tight. If your team is OpenAI-first elsewhere, the Codex integration is meaningful. The cloud-run model is also good for "delegate this and walk away" patterns.
Use Cursor when the work is in-editor pair programming — see Cursor vs Claude Code. Codex CLI is competitive but Cursor's IDE features (debugger, syntax highlighting, in-editor chat) are unique to Cursor.
Don't pay for both unless you actually use both. The marginal value of paying for Codex if you already have Claude Code Max is small for most engineers — the workflows overlap significantly.
For teams: standardize. Mixed tooling across a team creates code review friction. Pick one (usually Claude Code or Cursor) and standardize.
How to evaluate yourself
Test both for a week on your actual work:
- Pick 5 representative tasks (a bug fix, a feature, a refactor, a test-writing task, a code-review task)
- Run each task in both Codex and Claude Code
- Score: time to completion, correctness on first try, total tokens used, subjective fatigue
- Compare
What you'll typically find: Claude Code wins on correctness and time-to-completion for hard tasks; Codex wins on integration with cloud-based async workflows. Most senior engineers settle on Claude Code for primary work and Codex (or Cursor) as a secondary tool.
FAQ
Is Codex better than Claude Code? For raw coding ability, Claude Code is currently ahead — Sonnet 4.6 / Opus 4.7 lead on coding benchmarks and our production traces. Codex is competitive and improving. The decision often comes down to ecosystem fit and workflow preference (cloud vs local).
Which is cheaper? Depends on your usage pattern. Claude Code Max ($100/mo) is cheaper than ChatGPT Pro ($200/mo) at the mid-tier. Codex is cheaper at the API level (GPT-5.2-Codex at $1.75/$14 vs Sonnet at $3/$15).
Does Codex use GPT-5.5 or GPT-5.4? Neither. Codex runs GPT-5.2-Codex, a model purpose-built for the coding agent loop. It's optimized differently from the general-purpose GPT-5.x models.
Can I use Codex inside Cursor? Cursor lets you choose models. You can route Codex-suitable tasks to GPT-5.2-Codex via Cursor's settings. The Codex-as-product (the OpenAI app) and GPT-5.2-Codex (the model) are separate.
Is Claude Code only for terminal users? Primarily, yes. For an IDE-style experience using Anthropic's models, use Cursor with Claude selected, or the Claude consumer product.
Can I use both? Yes. Many engineers do — Claude Code for hard tasks where Anthropic models lead, Codex for OpenAI-integrated workflows. The two don't conflict; they share files.
Which has better integration with Git? Both integrate well with Git. Claude Code's terminal-native design feels more natural; Codex's cloud-run model is slightly more removed from Git workflow but works.
Which is better for teams? Claude Code Premium ($125/seat) is more expensive per-seat than Codex Enterprise ($25-40/seat) but includes the Claude consumer product alongside the coding agent. For team standardization, both work.