(l-onnx-doc-SequenceLength)=

# SequenceLength


(l-onnx-op-sequencelength-11)=

## SequenceLength - 11

### Version

- **name**: [SequenceLength (GitHub)](https://github.com/onnx/onnx/blob/main/docs/Operators.md#SequenceLength)
- **domain**: `main`
- **since_version**: `11`
- **function**: `False`
- **support_level**: `SupportType.COMMON`
- **shape inference**: `True`

This version of the operator has been available
**since version 11**.

### Summary

Produces a scalar(tensor of empty shape) containing the number of tensors in 'input_sequence'.

### Inputs

- **input_sequence** (heterogeneous) - **S**:

  Input sequence.

### Outputs

- **length** (heterogeneous) - **I**:

  Length of input sequence. It must be a scalar(tensor of empty shape).

### Type Constraints

* **S** in ( `seq(tensor(bool))`, `seq(tensor(complex128))`, `seq(tensor(complex64))`, `seq(tensor(double))`, `seq(tensor(float))`, `seq(tensor(float16))`, `seq(tensor(int16))`, `seq(tensor(int32))`, `seq(tensor(int64))`, `seq(tensor(int8))`, `seq(tensor(string))`, `seq(tensor(uint16))`, `seq(tensor(uint32))`, `seq(tensor(uint64))`, `seq(tensor(uint8))` ):

  Constrain to any tensor type.
* **I** in ( `tensor(int64)` ):

  Constrain output to integral tensor. It must be a scalar(tensor of empty shape).