One of the first things you want to do after installing WordPress on your website is adjusting the Maximum File Upload Size under My Sites >> Network Admin >> Settings. This article assumes you have enabled multisite when installing WordPress. If you didn’t, then the instructions would be slightly different, but you can still get the drift in this article.
When you do a fresh WordPress installation, the maximum file size you can upload is just 1500 KB or 1.5 MB. The average photo is about 1000 KB or 1 MB. So then, some large or high resolution photos wouldn’t be possible to upload with WordPress’ default settings, much less bigger files such as videos.
The thing is that WordPress assumes you need to save space on your webhost plan, so it starts you off with the bare minimum. Fortunately, you can change this setting easily. Simply hover your mouse over My Sites, then Network Admin, then Settings. The Network Settings page will then load. Look towards the bottom of the page and you will see “Max Upload File Size.” You will see that it is set to 1500 KB. You can increase that to a virtually infinite size by simply adding many zeros to the back of the number. Change it, for example, to 150000000000000000. Now that’s enough to upload some hours-long videos, and if it sticks, you can simply add more zeroes.
Chances are, you won’t need to upload really huge files on most WordPress site. You can also host them on third-party sites such as YouTube and embed them on your WordPress page or post. Remember to check your web hosts’ storage limit, and remember that uploading too many huge files can slow down or even crash your website.