How to get the best video quality?

First of all, there are many factors that can affect your video quality such as:

1. Video resolution - The best video resolution very much depends on the type of device you are using, as well as your internet connection. Sometimes watching a video in lower resolution is better than not watching it at all! SD resolutions are definitely a good option when it comes to mobile phones and tablets since they load faster and the screen itself is not that big. HD will absolutely give you a better experience on laptops, computer monitors, and TVs, but it requires a faster and better internet connection. 
2. Video compression - In order to compress a video without reducing the resolution, you need to find a good compression tool that will not affect it. 
3. The speed of your internet connection 
4. Video player/screen size - the 16:9 is commonly used for video making and is usually capable of supporting the highest resolution for horizontal videos, while 9:16 is typically used for vertical ones. 

You can find more about video resolution and quality on this blog post:

https://publit.io/community/blog/video-resolution-video-quality-explained 

There are a few things you need to know if you want to achieve the best video quality using Publitio:

• When uploading your video, the height needs to be at least 1080p so our system can convert the highest possible version. If the file height is 480p, we can’t convert it to 720p or 1080p. Publitio works best with 1080p+ formats and guarantees that all versions will be top-notch.
• With Publitio, you control the default quality of video through the player. The player will play 480p videos by default (lower quality), so users can switch to a better resolution via the cog icon on the player, or you can configure the player to set the default quality of all videos you play with it to 1080p.

https://support.publit.io/hc/en-us/articles/360007774777-How-to-change-default-video-quality-for-player- 

Publitio offers unlimited URL-based file transformations for all types of accounts and you can perform file transformations on the fly as much as you want.