# Generating checksums for a file

An MD5 checksum is a 32-character hexadecimal number that's computed on files. A SHA-256 checksum is an equivalent 64-character hexadecimal number. These values can be used to verify data integrity against unintentional file corruption during transfer.

**Generating MD5 Checksum**

**Windows**

1. Open **Command Prompt** - Press Windows + R, type cmd and press enter.
2. Navigate to the folder that has the file for which the integrity needs to be verified: type `cd` followed by the path to the folder having the file to do so.

Tip: Open the folder having the file in Windows Explorer, then drag and drop it in Command Prompt to inset the path.

3. Type the following command.

```
certutil -hashfile <File whose MD5 needs to be computed> MD5  
```

```
certutil -hashfile <File whose SHA256 needs to be computed> SHA256  
```

For example, in order to generate the MD5 checksum for a Oracle Linux 8 ISO file:

![](/files/DXOASOAOiy5b6ywSNuHk)

**Linux**

1. Open **Terminal**
2. Navigate to the folder that has the file for which the integrity needs to be verified: type `cd` followed by the path to the folder having the file to do so.
3. Run the following command.

```
md5sum <File whose MD5 needs to be computed>  
```

```
sha256sum <File whose SHA256 needs to be computed>  
```

For example, in order to generate the MD5 checksum for a Oracle Linux 8 ISO file:

![](/files/S9p5Ksa7RvnWGuuxTVSQ)

Verify if the **estimated MD5/SHA-256** **matches** the **MD5/SHA-256 value provided by the file's original owner**. If the two checksums are different, the **file is likely corrupted**. Re-transfer the file and repeat the process.

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| *For any feedback or questions regarding this article (Illumina Knowledge Article #8482), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000008482%20-%20Software%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |


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