GPT-5.5 vs Claude Opus 4.8: which should you use?

These are the two frontier models most people actually reach for in 2026. Both are excellent. But "they are both great, pick whichever" is a cop-out, so let us call it.

Intelligence and coding

Claude Opus 4.8 edges ahead on the hardest coding, leading SWE-bench Pro at 69%. GPT-5.5 is the stronger generalist and ships with native web search, which matters more than a benchmark point or two when your task touches the live internet.

Context and price

Opus carries the bigger context window, which is the difference between pasting your whole repo and playing tokenizer Tetris. Pricing sits close at the frontier tier. For the current side-by-side numbers, see the full comparison.

Speed

In our own latency tests, GPT-5.5 was the quicker of the two, landing around 2.0s median on short answers versus about 3.1s for Opus. If snappiness is what makes a model feel good to use, that gap is noticeable.

The verdict

• Pick Opus 4.8 for the hardest coding and long-context reasoning, where correctness is everything.
• Pick GPT-5.5 for fast, general work, especially anything that benefits from web search and tools.

Still torn? Do not take our word for it. On TryAI you can run both on one account and let your own prompts decide.