Using several AI models together reliably beats using one. There are two ways to do it: routing and fusion.
Routing: the right model per task
Send each part of your work to the model that's best at it — code to a code-strong model, images to an image-strong model, reasoning to a reasoning-strong model. The hard part by hand is knowing which is which and moving content between tools.
Fusion: cross-checking one task
For high-stakes work, run the same task through several models and synthesize the best answer. Public benchmarks have shown a fused answer can beat the best single model — because different models catch different things, like getting a second opinion.
When fusion is worth it
Use it when accuracy matters more than speed or cost: a board paper, a legal-adjacent summary, an important client deliverable. For everyday tasks, single-model routing is plenty.
Doing it without the busywork
The manual version of this is slow — multiple tabs, multiple subscriptions, manual comparison. Ensemble automates both routing and fusion, so you get the multi-model result from a single prompt.