# tf.keras.backend.flatten

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|---|---|
| [![](https://www.tensorflow.org/images/tf_logo_32px.png) TensorFlow 2 version](https://www.tensorflow.org/api_docs/python/tf/keras/backend/flatten) | [![](https://www.tensorflow.org/images/GitHub-Mark-32px.png) View source on GitHub](https://github.com/tensorflow/tensorflow/blob/v1.15.0/tensorflow/python/keras/backend.py#L2903-L2925) |

Flatten a tensor.

#### View aliases


**Compat aliases for migration**

See
[Migration guide](https://www.tensorflow.org/guide/migrate) for
more details.

[`tf.compat.v1.keras.backend.flatten`](https://www.tensorflow.org/api_docs/python/tf/keras/backend/flatten), \`tf.compat.v2.keras.backend.flatten\`

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    tf.keras.backend.flatten(
        x
    )

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| ## Arguments ||
|---|---|
| `x` | A tensor or variable. |

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| ## Returns ||
|---|---|
| A tensor, reshaped into 1-D ||

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#### Example:

    b = tf.constant([[1, 2], [3, 4]])
    b
    <tf.Tensor: id=102, shape=(2, 2), dtype=int32, numpy=
    array([[1, 2],
           [3, 4]], dtype=int32)>
    tf.keras.backend.flatten(b)
    <tf.Tensor: id=105, shape=(4,), dtype=int32,
        numpy=array([1, 2, 3, 4], dtype=int32)>