A good question. The war's most decisive US victory (The Battle of New Orleans)was fought after the peace treaty was signed at Ghent, but Britain captured a fort after that, anyway. Britain wanted to teach the US a lesson after we threatened to (and did) invade Britain's Canadian territory, and they succeeded. They captured Washington DC and burned down the White House. Sounds like a good case that the US lost.
Canadians celebrated the end of the war as a victory because their invasion never happened, but they did lose control of portions of land to Britain south of Lake Superior that they hoped to control. Britain's main goal was to prevent the US from aiding France during the War with Napoleon. After Napoleon was defeated, they no longer had that worry, and they lost interest. Both sides were glad to end the war.
You be the judge.
I meant to write:
..but British Canada did lose control of disputed land south of Lake Superior that they had hoped to control.