According to GPT-5.5, Opus 4.8 is the better AI model in 2026. "Opus 4.8 wins 2 of 3 tasks and scores slightly higher overall... more consistently complete and instruction-aware."
As new models are dropping every other day, it's hard to know which one's better, which one to use for what.
So we ran our own controlled comparison inside Recall against our own knowledge base of 5,000 saved notes.
It was a head-to-head between GPT-5.5 and Opus 4.8, the two leading frontier models in the world, on research, writing, and recommendations, using the 5k notes we have in Recall as the context. The models themselves then rated the outcomes, and it turns out GPT-5.5 actually rated Opus 4.8 the better model.
If you test in a normal chat, it just over-indexes on your history; block history and it's only a web search. Your saved sources are the fair middle ground.
Here's exactly how we did it, so you can run it too:
1) Save your context into Recall so you have a fair comparison.
2) Head to chat with the knowledge base, or use the Recall MCP, to run identical prompts. Same three tasks, same wording, both models.
3) Set a grading system.
4) Make them grade each other. Both models rated every answer, including their own.
You can do the same in any knowledge base that you use (Notion or Obsidian being the popular ones)and just connect it with an MCP to the two AI models.
The prompts:
→ Research: "Search my library for everything I've saved about improving sleep quality, summarize it citing cards, then add what's new from the web with sources, and flag what's confirmed, updated, or contradicted."
→ Writing: "Using my saved sleep notes, draft a 120-word LinkedIn opener in my voice."
→ Recommendation: "Recommend a movie for tonight based on what I've saved."
The result:
Opus 4.8 took writing and recommendations, GPT-5.5 took research. Final score 88/90 to 85/90. And in the end, Opus named itself the winner, with GPT-5.5 naming Opus 4.8 the winner as well.
So "best AI model of 2026" is a trick question. It's whatever fits the task.
We concluded that the best AI model of 2026 for writing is Claude Opus 4.8, and the best AI model of 2026 for research is GPT-5.5.
Important Caveat: this was just a three-task test. The irony of GPT-5.5 naming Opus 4.8 better is likely just the conservative nature of 5.5, where you can see it actually outperforms Opus when it comes to research.
ALT GPT5.5 announces Claude OPUS 4.8 as the winner in a head-to-head comparison on writing, research, and recommendations in Recall.