---
title: Versioning (v2.4)
description: API reference for Versioning in qiskit-c v2.4
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit-c/2.4/version
---

# Versioning

Qiskit’s version can be queried using a set of compiler macros.

### QISKIT\_VERSION

A human-readable version as `char*`. For example: `"2.1.0-rc1"`.

### QISKIT\_VERSION\_HEX

The version number as 4-byte hexadecimal. The format is `0xMMmmppls`, where `M` is the major, `m` is the minor, `p` is the patch, `l` is the release level and `s` is the serial. For example, 2.1.0-rc1 is `0x020100C1`.

Note that final versions, such as `2.1.0`, will always end with `0xF0` in the last byte.

See [`qk_api_version()`](#qk_api_version "qk_api_version") for the runtime version of this.

### QISKIT\_VERSION\_MAJOR

The major release version.

### QISKIT\_VERSION\_MINOR

The minor release version.

### QISKIT\_VERSION\_PATCH

The patch release version.

### QISKIT\_RELEASE\_LEVEL

The release level:

- `0xA` for an unreleased dev (or alpha) version
- `0xB` for a beta version
- `0xC` for a release candidate
- `0xF` for a stable (or final) version.

### QISKIT\_RELEASE\_SERIAL

This can be used to indicate the pre-release number in a pre-release series. For example, this would be set to `4` for `2.1.0-rc4`. This is `0` for the final version.

### QISKIT\_GET\_VERSION\_HEX(major, minor, patch, level, serial)

A macro to pack the version numbers into hexadecimal format. This can be used as tool to compare numbers, for example to ensure the current version is at least the stable 2.1.0 release do:

```c
if (QISKIT_VERSION_HEX >= QISKIT_GET_VERSION_HEX(2, 1, 0, 0xF, 0)) {
    // Code for version 2.1.0 (final) or later
}
```

### qk\_api\_version

`uint32_t qk_api_version(void)`

Get the C API version of the loaded library.

If you are dynamically linking against Qiskit, in either a stand-alone or Python-extension build, this function can be useful to check the version of the library actually loaded at runtime. The header-file macro `QISKIT_VERSION_HEX` is the equivalent of this function, but for the version of the headers used at build time.

**Returns**

The version of the compiled Qiskit C API library, in the same format as the `QISKIT_VERSION_HEX` header-file macro.