Best Claude model for research
For research with Claude, use Opus 5.5 at high effort.
Opus 5.5 at high effort
High efforteffort = high
Top score on the Artificial Analysis Intelligence Index (58, measured at max effort) at 40% of Fable's price. If Opus at max effort still falls short, try Fable.
How it compares
Prices are in US dollars per million tokens, input then output. Opus 5.5 costs $4 / $20.
| Model | Price | Against the pick |
|---|---|---|
| Fable 5.1 | $10 / $50 | Anthropic's strongest, at 2.5x the price. Anthropic itself says start on Opus and step up only if it falls short. |
| Sonnet 5.5 | $2 / $10 | Close behind (56.0) at half the price, so the one to use on a budget. |
| Haiku 5.5 | $0.10 / $0.50 | Too light for deep work. |
Setting it in the API
In an API request, set the model and effort like this:
model: "claude-opus-5-5", output_config: { effort: "high" }
Maintained by the AI team at Vegan Hacktivists
Prices are per million tokens, input / output. We pick for the best result per dollar, so a pricier model can score higher and still lose out. This pick last changed Oct 9, 2026. Sources: Anthropic docs, OpenAI docs, Gemini docs, Artificial Analysis, Vals AI.Last checked Oct 12, 2026.
Other picks
Claude for code, everyday work, agents and automations.
Other labs for research: OpenAI, Gemini.
Open the interactive picker to switch between labs and tasks.
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