A floor loom in your browser. Thread it, tie up the treadles, choose what to press on each pick, and watch the cloth come off the loom one thread at a time.
Click a square to change it. In the threading, each end goes on one shaft; in the tie-up, a mark ties a shaft to a treadle; in the treadling, a mark is the treadle you press for that pick. Shift-click presses two treadles at once. The drawdown works itself out. The colored strips along the top and right are the warp and weft colors: pick a color below and paint them. Keyboard: arrows move, Enter or Space changes a square, Shift+Enter adds a second treadle.
Print a plain black and white draft for the loom bench, with the threading and treadling written out as numbers. Or save it as a WIF file, the plain text format weaving programs use to swap drafts, and open it again here later.
A weaving draft is the small map a weaver works from. Along the top is the threading: which shaft each warp end passes through. Top right is the tie-up: which shafts each treadle is tied to. Down the right is the treadling: which treadle to press for each pick of weft. The big grid is the drawdown, and nobody draws it by hand if they can help it. It follows from the other three: a square is dark where that warp end is lifted over that pick.
The cloth beside it is the same draft, woven across a scarf's width of warp, one pick at a time. Color alone makes some patterns: houndstooth is an ordinary twill with four dark threads and four light, in both directions. Press "Weave it yourself" to go pick by pick and see which shafts rise.
Everything happens on this page. Nothing you weave is sent anywhere or kept after you close it.