What is transcoding?
Converting a video or audio file from one codec, container or bitrate to another - decompressing it, then compressing it again in the new format.
Every social platform transcodes what you upload, whatever format it arrived in, to its own internal delivery format - this is why uploading the highest possible quality rarely changes what a viewer eventually sees; the platform re-compresses it regardless.
Re-encoding between lossy codecs (for example, H.264 in MOV to VP9 in WebM) discards additional information at the encoding step; decoding does not add another lossy generation, so quality can degrade slightly even when the settings look equivalent - a plain container change (MOV to MP4 with the same codec inside) avoids this because no re-compression happens.
Koldflux picks the right codec, container and bitrate for every platform automatically - this glossary exists because our own team had to get it right first.
Automate this in Koldflux