# Codec question
**URL:** https://forums.plex.tv/t/codec-question/227190
**Category:** General Discussions
**Created:** [February 27, 2018, 3:01pm UTC](https://forums.plex.tv/t/codec-question/227190 "2018-02-27T15:01:26Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@jlim0930](https://forums.plex.tv/u/jlim0930)
#### Post date: [February 27, 2018, 3:01pm UTC](https://forums.plex.tv/t/codec-question/227190/1 "2018-02-27T15:01:26Z")
What is the most widely used codec for video and audio that will provide the most compatibility across devices such as iphone/ipad/android/plex/kodi ? without having to transcode much on the server/client ends in general ?
is it H264/aac or some other combination?
I am slowly transitioning my kodi setup to plex and before it wasn’t a problem of having any codec’s since the transcode happens on kodi devices but on plex the transcoding happens on the server and with multiple streams it gets a bit overloaded.
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### Author:  [@SiscoPlex](https://forums.plex.tv/u/SiscoPlex)
#### Post date: [February 27, 2018, 5:58pm UTC](https://forums.plex.tv/t/codec-question/227190/2 "2018-02-27T17:58:43Z")
Video: H264, level 4.1, optimized for streaming in an mp4 container.
Audio: AAC or AC3
Subs: SRT
I avoid subtitles if at all possible, otherwise I hard encode them(burn) them into the video.
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### Author:  [@system](https://forums.plex.tv/u/system)
#### Post date: [January 8, 2020, 12:41am UTC](https://forums.plex.tv/t/codec-question/227190/3 "2020-01-08T00:41:03Z")