Is GPT-5.5 Codex better than Claude Code?

On raw agentic benchmarks, yes: GPT-5.5 hits 82.7% on Terminal-Bench 2.0 vs Claude Opus 4.7's 69.4%. But on SWE-bench Verified — which measures real GitHub issue resolution — Claude Opus 4.7 still wins 87.6% vs 78.2%. In practice, Claude Code is better at deep refactors and multi-file changes; GPT-5.5 Codex is better at open-ended tasks that require web browsing, computer use, or long autonomous runs.

Which agent can run longer without supervision?

GPT-5.5 Codex, with Dynamic Reasoning Time of 7+ hours on a single task. Claude Code typically runs productive autonomous sessions of 30–90 minutes before requiring a checkpoint. For overnight or multi-hour autonomous work, GPT-5.5 Codex has the longer horizon. For interactive pair-programming where you review each change, Claude Code is more responsive.

Which is cheaper, GPT-5.5 Codex or Claude Code?

GPT-5.5 Codex is dramatically cheaper per token: $1.50 input / $12 output vs Claude Opus 4.7's $15 input / $75 output. But Claude Code can also run on Sonnet 4.6 ($3 / $15), which is cheaper than GPT-5.5 on the API. For most developers, the practical cost gap narrows on the $20/month ChatGPT Plus vs $20/month Claude Pro subscriptions — both include generous agent usage.

Do GPT-5.5 Codex and Claude Code both work in VS Code?

Yes. GPT-5.5 Codex has an official VS Code extension (the Codex IDE extension) plus a CLI (Codex CLI). Claude Code has an official VS Code extension plus CLI as well. Both support background agents. Claude Code is also available in JetBrains IDEs; the Codex IDE extension is currently VS Code-only.

Quick Answer

GPT-5.5 Codex vs Claude Code (Opus 4.7): April 2026

Published: April 24, 2026

GPT-5.5 Codex vs Claude Code (Opus 4.7): April 2026

The two most powerful coding agents in production just leapfrogged each other within a week. Anthropic’s Claude Code (running on Opus 4.7) hit a new SWE-bench record on April 16. OpenAI’s Codex (running on GPT-5.5) took back Terminal-Bench 2.0 on April 23. Here’s which one to actually use.

Last verified: April 24, 2026

TL;DR

	GPT-5.5 Codex	Claude Code (Opus 4.7)
Model	GPT-5.5	Claude Opus 4.7
Released	April 23, 2026	April 16, 2026
SWE-bench Verified	78.2%	87.6%
SWE-bench Pro	58.6%	64.3%
Terminal-Bench 2.0	82.7%	69.4%
GDPval	84.9%	79.3%
Max autonomous run	7+ hours	~90 min effective
Computer use	Native	Via MCP/tools
Input $/1M tokens	$1.50	$15
IDE integration	VS Code	VS Code, JetBrains
Subscription option	ChatGPT Plus $20/mo	Claude Pro $20/mo

What each agent actually is

GPT-5.5 Codex

A family of surfaces, all backed by GPT-5.5:

Codex CLI — terminal agent
Codex IDE extension — VS Code
Codex Cloud — cloud-based background agents with compute sandboxes
Codex Skills — the agentic toolkit (read-only production access, command-line interfaces)
Codex SDK — for building custom agents on GPT-5.5

OpenAI says GPT-5.5 is “purpose-built for Codex CLI, the Codex IDE extension, the Codex cloud environment, and working in GitHub, and also supports versatile tool use.” NVIDIA uses the Codex stack internally for automation workflows.

Claude Code

Anthropic’s first-party coding agent:

Claude Code CLI — terminal agent (claude command)
Claude Code VS Code extension
Claude Code JetBrains plugin
Claude Code Background Mode — autonomous long-running tasks
MCP integration — full Model Context Protocol support for tool use

By default, Claude Code runs on Opus 4.7 (since April 16). You can configure it to use Sonnet 4.6 for cheaper runs.

Benchmark winners by category

Task type	Winner	Why
Resolve real GitHub issues	Claude Code	SWE-bench Verified lead (87.6% vs 78.2%)
Industry-realistic codebases	Claude Code	SWE-bench Pro lead (64.3% vs 58.6%)
Terminal / shell automation	Codex	Terminal-Bench 2.0 (82.7% vs 69.4%)
Autonomous multi-step agents	Codex	GDPval (84.9% vs 79.3%)
Tool-use dialogs	Codex	τ²-Bench Telecom (79.1% vs 74.2%)
Deep multi-file refactors	Claude Code	1M context + SWE-bench dominance
Computer use / browser automation	Codex	Native computer use in GPT-5.5
Running for 4+ hours unattended	Codex	Dynamic Reasoning Time 7+ hrs
Pair programming with reviews	Claude Code	Faster turn-around on small changes

Where each agent breaks down

Claude Code weaknesses in April 2026

Computer use requires MCP. Browser automation needs a separate MCP server (Playwright MCP, etc.). GPT-5.5 Codex has native computer use.
Shorter autonomous horizon. Claude Code sessions drift after ~90 minutes. Codex runs 7+ hours.
Opus 4.7 is expensive. At $15/$75 per million tokens, long-running Claude Code sessions can easily spend $20–50 per task. Switch to Sonnet 4.6 for routine work.
Slower. Opus 4.7 generates ~55 tokens/sec vs GPT-5.5’s ~150 tokens/sec. A 10K-token response takes 3x longer in Claude Code.

GPT-5.5 Codex weaknesses in April 2026

Worse at SWE-bench. On real GitHub issues, Claude Code’s Opus 4.7 still wins by 9.4 points. If your work is mostly “fix this bug in our repo,” Claude Code is the safer bet.
400K context vs Claude Code’s 1M. On monorepos, GPT-5.5 needs chunking.
Less mature MCP ecosystem. Claude Code has a bigger third-party MCP library as of April 2026 (Anthropic shipped MCP a year earlier).
VS Code only for the IDE extension. JetBrains users still need Codex CLI.

When to use each

Use GPT-5.5 Codex when:

You need a long-running background agent (>2 hours unattended)
You’re doing computer use, browser automation, or UI testing
Cost matters — GPT-5.5 is 10x cheaper than Opus 4.7 per token
You want tight integration with GitHub Actions / cloud runners
Your codebase fits in 400K tokens
You’re already using ChatGPT Plus/Pro

Use Claude Code (Opus 4.7) when:

You need to resolve complex GitHub issues in a production codebase
You do large-PR refactors across 30+ files
You use JetBrains IDEs (not just VS Code)
You have a mature MCP tool stack
You want the current SWE-bench state of the art
You’re already paying for Claude Pro or Max

Use Claude Code (Sonnet 4.6) when:

You want Claude Code’s UX but at a fraction of the cost
Daily incremental coding work where Opus 4.7 is overkill
You’re price-sensitive but want the Claude ecosystem

The subscription math

At $20/month, both ChatGPT Plus and Claude Pro offer full access to their respective coding agents with practical usage caps. For solo developers, the choice is rarely about price — it’s about:

Which model fits your work? (Deep refactors → Claude; long autonomous runs → Codex)
Which IDE do you use? (JetBrains → Claude Code; VS Code → either)
How tolerant are you of flakiness? (Production coders tend to prefer Claude Code’s stability)

For teams doing >$200/month of agent work via API, GPT-5.5’s pricing is compelling enough to run parallel workflows on both and route by task type.

The meta-lesson

One week ago, Claude Code was uncontestably the best coding agent in production. Today, it’s a split decision. That cycle will repeat — probably before June 2026.

The practical answer: build behind an abstraction (OpenRouter, LiteLLM, a custom router). Keep both Codex and Claude Code installed. Route by task type. Swap the default every time a new model ships. Your real benchmark is your own workload.

Last verified: April 24, 2026. Sources: OpenAI GPT-5.5 announcement, OpenAI Codex docs (developers.openai.com/codex), Anthropic Opus 4.7 model card, Claude Code docs, VentureBeat, Fortune, NVIDIA Blog, LLM-Stats, BenchLM.