.. _op_ai_onnx_Constant:

Constant
========

- **Domain**: ``ai.onnx``
- **Since version**: 25

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(float8e8m0), tensor(int16), tensor(int2), tensor(int32), tensor(int4), tensor(int64), tensor(int8), tensor(string), tensor(uint16), tensor(uint2), tensor(uint32), tensor(uint4), tensor(uint64), tensor(uint8).

Differences with previous version (24)
--------------------------------------

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

* old version: 24
* new version: 25
* breaking: no

**Type constraints:**

* changed 'T': added types: ['tensor(int2)', 'tensor(uint2)']

Version History
---------------

- :doc:`Version 24 <Constant-24>`
- :doc:`Version 23 <Constant-23>`
- :doc:`Version 21 <Constant-21>`
- :doc:`Version 19 <Constant-19>`
- :doc:`Version 13 <Constant-13>`
- :doc:`Version 12 <Constant-12>`
- :doc:`Version 11 <Constant-11>`
- :doc:`Version 9 <Constant-9>`
- :doc:`Version 1 <Constant-1>`