keras-team/keras · error · ValueError

Cannot do batch_dot on inputs with different batch sizes. Re

Error message

Cannot do batch_dot on inputs with different batch sizes. Received inputs with shapes {x_shape} and {y_shape}.

What it means

Error "Cannot do batch_dot on inputs with different batch sizes. Received inputs with shapes {x_shape} and {y_shape}." thrown in keras-team/keras.

Source

Thrown at keras/src/layers/merging/dot.py:72

    y_shape = y.shape

    x_ndim = len(x_shape)
    y_ndim = len(y_shape)

    if x_ndim < 2 or y_ndim < 2:
        raise ValueError(
            f"Cannot do batch_dot on inputs "
            f"with rank < 2. "
            f"Received inputs with shapes "
            f"{x_shape} and {y_shape}."
        )

    x_batch_size = x_shape[0]
    y_batch_size = y_shape[0]

    if x_batch_size is not None and y_batch_size is not None:
        if x_batch_size != y_batch_size:
            raise ValueError(
                f"Cannot do batch_dot on inputs "
                f"with different batch sizes. "
                f"Received inputs with shapes "
                f"{x_shape} and {y_shape}."
            )
    if isinstance(axes, int):
        axes = [axes, axes]

    if axes is None:
        if y_ndim == 2:
            axes = [x_ndim - 1, y_ndim - 1]
        else:
            axes = [x_ndim - 1, y_ndim - 2]

    if any(isinstance(a, (list, tuple)) for a in axes):
        raise ValueError(
            f"Multiple target dimensions are not supported. "
            f"Expected: None, int, (int, int), "

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/layers/merging/dot.py:72 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of keras-team/keras@7a34a03db6 (2026-08-25). Data as JSON: /api/errors/88b04b08bf53e230. Report an issue: GitHub.