GPT-5.5 vs Claude Opus 4.7: The April 2026 Showdown

April 2026 just became the most competitive week in AI history. On April 16, Anthropic shipped Claude Opus 4.7 — reclaiming the coding crown on SWE-bench. On April 23, OpenAI answered with GPT-5.5 (codename “Spud”), a fully retrained agentic model that narrowly tops Terminal-Bench 2.0. Here’s the head-to-head that actually matters.

Last verified: April 24, 2026

TL;DR

Metric	GPT-5.5	Claude Opus 4.7
Released	April 23, 2026	April 16, 2026
Input price / 1M tokens	$1.50	$15
Output price / 1M tokens	$12	$75
Context window	400K	1M
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%
τ²-Bench Telecom	79.1%	74.2%
Tokens/sec (first token)	~150	~55
Real-time web + computer use	✅ native	Via tools/MCP

Bottom line: GPT-5.5 wins on agentic computer use, speed, and price. Opus 4.7 wins on deep coding and long-context.

What’s actually new about GPT-5.5

OpenAI president Greg Brockman called GPT-5.5 “a new class of intelligence” and “a big step towards more agentic and intuitive computing.” In practice, three things changed:

1. Fully retrained, not a fine-tune. Unlike the 5.1 → 5.4 incremental path, 5.5 is a clean-slate training run.
2. Computer use is native. GPT-5.5 can interact with web apps, click through pages, test flows, capture screenshots, and iterate on what it sees — all without a plugin layer.
3. Longer autonomous horizons. The Codex integration supports Dynamic Reasoning Time of up to 7+ hours on a single task. Background agents can now receive transcript deltas and stay silent when appropriate.

Axios confirmed the “Spud” codename. The release was one week after Anthropic’s Opus 4.7 and one day after Anthropic’s Mythos Preview coverage peaked — the cadence that Fortune called “AI model launches starting to look like software updates.”

Where each model wins

GPT-5.5 strengths

• Best agentic benchmarks. 82.7% on Terminal-Bench 2.0 vs Opus 4.7’s 69.4% is a 13-point gap — huge for autonomous tasks.
• Best GDPval. 84.9% — the benchmark for economically valuable knowledge work.
• Cheapest frontier agent. $1.50/$12 per million is roughly 10x cheaper than Opus 4.7.
• 3x faster. ~150 tokens/sec vs Opus 4.7’s ~55. Matters a lot when an agent generates 50K tokens of tool calls.
• Native computer use. No CUA plugin required, no extra setup.
• Strongest on τ²-Bench Telecom (79.1%) — a real-world multi-turn tool-use benchmark.

Claude Opus 4.7 strengths

• Best SWE-bench Verified. 87.6% is the highest ever recorded — 9.4 points over GPT-5.5.
• Best SWE-bench Pro. 64.3% vs 58.6%. On the harder industry-realistic version of SWE-bench, Opus 4.7 is still ahead.
• 1M context window. Opus 4.7’s 1M vs GPT-5.5’s 400K matters for monorepo work and document-heavy agents.
• Cursor and Claude Code dominance. Opus 4.7 has shipped in production agent harnesses for a week longer and is the default in both major paid coding agents.
• Better at large-PR refactors. Real-world multi-file refactors on 30K+ line codebases still favor Opus 4.7 in community testing.

The benchmark gap decoded

The same LLM-Stats aggregate I pulled shows Opus 4.7 leading on 6 of 10 shared benchmarks, GPT-5.5 on 4, with margins between 2 and 13 points. But BenchLM’s provisional composite says GPT-5.5 leads 89 to 86 across agentic, coding, multimodal, knowledge, and reasoning.

How can both be true? Because the two models are optimized for different axes:

• Opus 4.7 is the better coder when you give it a specific, well-scoped coding task.
• GPT-5.5 is the better agent when you hand it an open-ended goal and let it plan, browse, test, and iterate.

If your workload is “refactor this React app to use Zustand,” Opus 4.7 wins. If your workload is “look at our production dashboard, figure out why checkout is broken, and fix it,” GPT-5.5 wins.

Pricing reality check

A typical “agentic” task burns 50K input tokens and 10K output tokens across tool calls. Here’s what that costs:

Model	Per-task cost
GPT-5.5	$0.20
Claude Opus 4.7	$1.50
Claude Sonnet 4.6	$0.30
Gemini 3.1 Pro	$0.16

Multiply by 1,000 agent runs per day and GPT-5.5 saves you $1,300 vs Opus 4.7. That’s the real story of April 2026: the price-performance frontier has collapsed again in OpenAI’s favor.

Which should you default to?

• “I’m building production AI agents”: GPT-5.5. Better agentic benchmarks, 10x cheaper, 3x faster.
• “I code for a living in Cursor or Claude Code”: Stick with Opus 4.7 (or Sonnet 4.6 for daily work). SWE-bench Verified still matters.
• “I need computer use / browser automation”: GPT-5.5 native computer use is the new default.
• “I need long-context reasoning (>400K tokens)”: Opus 4.7 (1M) or Gemini 3.1 Pro (2M).
• “I want the cheapest smart model”: GPT-5.5 — or GPT-5.5 mini (when it ships) for batch workloads.

The bigger picture

Three weeks ago, the frontier was Gemini 3.1 Ultra. Two weeks ago, Claude Mythos Preview. One week ago, Opus 4.7. Today, GPT-5.5. The AI model release cycle has compressed from yearly to weekly, and the practical lead swaps hands on each release.

For production systems in April 2026, the playbook is:

1. Build behind an abstraction. Use OpenRouter, LiteLLM, or a custom router so you can swap models without rewrites.
2. A/B test on your real traffic. Benchmarks disagree; your workload is the only benchmark that matters.
3. Default to cheap and fast. GPT-5.5 or Sonnet 4.6 for 90% of traffic, Opus 4.7 for hard tasks.

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Last verified: April 24, 2026. Sources: OpenAI GPT-5.5 announcement (openai.com/index/introducing-gpt-5-5), VentureBeat, LLM-Stats, BenchLM, Anthropic Opus 4.7 model card, Terminal-Bench 2.0 maintainers, Fortune, Axios.