.. _op_ai_onnx_Constant-23:

Constant - version 23
=====================

This page documents version **23** of operator **Constant**. See :doc:`Constant` for the latest version (since version 25).

- **Domain**: ``ai.onnx``
- **Since version**: 23

This operator produces a constant tensor. Exactly one of the provided attributes, either value, sparse_value,
or value\* must be specified.

**Outputs**

- **output** (*T*): Output tensor containing the same value of the provided tensor.

**Type Constraints**

- **T**: Constrain input and output types to all tensor types.
  Allowed types: tensor(bfloat16), tensor(bool), tensor(complex128), tensor(complex64), tensor(double), tensor(float), tensor(float16), tensor(float4e2m1), tensor(float8e4m3fn), tensor(float8e4m3fnuz), tensor(float8e5m2), tensor(float8e5m2fnuz), tensor(int16), tensor(int32), tensor(int4), tensor(int64), tensor(int8), tensor(string), tensor(uint16), tensor(uint32), tensor(uint4), tensor(uint64), tensor(uint8).

Differences with previous version (21)
--------------------------------------

**SchemaDiff**: ``Constant`` (domain ``'ai.onnx'``)

* old version: 21
* new version: 23
* breaking: no

**Type constraints:**

* changed 'T': added types: ['tensor(float4e2m1)']