Claude Opus 4.6 vs GPT-5.2: How Do They Compare?
With Claude Opus 4.6 launching in February 2026 and GPT-5.2 arriving in December 2025, we now have two heavyweight frontier models to compare. Here's how they stack up across the dimensions that matter most for real-world work.
Overview
| Claude Opus 4.6 | GPT-5.2 | |
|---|---|---|
| Release | February 5, 2026 | December 11, 2025 |
| Developer | Anthropic | OpenAI |
| Context Window | 1M tokens (beta) | 1M tokens |
| Max Output | 128K tokens | 64K tokens |
| Variants | Single model with adaptive thinking | Instant, Thinking, Pro |
| Pricing (input/output) | $5 / $25 per 1M tokens | Varies by variant |
Coding
This is where the gap is most visible. Opus 4.6 scores highest on Terminal-Bench 2.0 for agentic coding tasks and has noticeably better performance on large codebase navigation and multi-file refactors.
GPT-5.2 countered with GPT-5.2-Codex, a specialized coding variant designed for long-horizon software engineering work. Codex brings context compaction and improved performance on migrations and large refactors, particularly in Windows environments.
Verdict: Opus 4.6 leads on general coding benchmarks. GPT-5.2-Codex is competitive for specialized long-running tasks.
Knowledge Work
On GDPval-AA — an evaluation covering finance, legal, and other professional domains — Opus 4.6 outperforms GPT-5.2 by approximately 144 Elo points. That's a meaningful gap.
However, GPT-5.2 Thinking claims to beat or tie top industry professionals on 70.9% of GDPval comparisons, which is also impressive.
Verdict: Opus 4.6 has the edge on structured knowledge work evaluations.
Reasoning & Thinking
Both models support extended thinking, but they approach it differently:
- Opus 4.6 uses adaptive thinking — the model decides when and how hard to think. You can also set effort levels (low, medium, high, max).
- GPT-5.2 offers three distinct variants: Instant (fast, lightweight), Thinking (deeper reasoning), and Pro (maximum accuracy). You choose the mode upfront.
Opus 4.6's adaptive approach is more seamless — you don't have to pick a mode. GPT-5.2's variant system gives you more explicit control over the speed/quality tradeoff.
Verdict: Different philosophies, both effective. Opus is more automatic; GPT-5.2 gives more manual control.
Long Context
Both models support 1M token contexts. But raw context window size isn't what matters — it's how well they use that context.
Opus 4.6 scores 76% on MRCR v2 for long-context retrieval, a massive jump from its predecessor's 18.5%. This means it can reliably find and use information buried deep in large inputs.
GPT-5.2's long-context performance is strong but Anthropic's benchmarks suggest Opus 4.6 has the retrieval advantage.
Verdict: Opus 4.6 appears stronger at actually utilizing long contexts.
Agentic Capabilities
This is where both models are pushing hardest:
- Opus 4.6 introduces agent teams in Claude Code — multiple agents splitting work in parallel, coordinated by a lead agent.
- GPT-5.2 emphasizes improved agentic tool-calling and end-to-end task execution.
Both are moving toward AI that doesn't just answer questions but actually does work. Opus 4.6's team-based approach feels more structured; GPT-5.2's improvements are more general-purpose.
Verdict: Opus 4.6 has the more innovative agentic architecture with teams. GPT-5.2 is solid for single-agent workflows.
Bottom Line
There's no single "winner." The right choice depends on your use case:
- Choose Opus 4.6 if you're doing heavy coding work, need strong long-context retrieval, or want to leverage agent teams for complex multi-step tasks.
- Choose GPT-5.2 if you want explicit control over reasoning modes (Instant/Thinking/Pro), need the specialized Codex variant for software engineering, or are already embedded in the OpenAI ecosystem.
Both models represent a significant step forward from where we were even six months ago. Competition is good — it means both keep getting better.