Best Video Codec Tutorials: 6 Free Videos That Make Codecs Click

Codecs make more sense after ten minutes of video than after ten pages of text, so here are the free tutorials worth your time, in the order to watch them.

Together they cover what a codec is, why a file extension tells you less than you think, and how compression squeezes a film into a file you can stream.

Start at the top if you are new, or skip to the deep dives if you already know what H.264 is.

After each video there is one thing to try on your own files, so the idea sticks.

Start Here: What a Codec Actually Is

What is a Codec as Fast As Possible - Techquickie. The quickest plain-English answer there is: a codec shrinks video to store it and unpacks it again to play it. Watch it on YouTube.

Then try: our guide to how codecs work behind the scenes walks through the same idea with the file on your own screen in mind.

Video Codecs 101 - the WebM Project. A short explainer from the team behind the VP8 and VP9 codecs, covering the basics of how video compression works. Watch it on YouTube.

Then try: see which codecs actually won in the 3 most popular video codecs used worldwide.

Next: Codecs vs Containers

This is the idea that fixes the most "why won't this play?" moments. MP4, MKV and AVI are boxes, and the codec is what is packed inside - two MP4 files can hold completely different video, and renaming a file never converts it.

Codecs and Formats Explained! (And Why You're Probably Wrong) - untangles the words people mix up - container, format and codec - and corrects a few common myths along the way. Watch it on YouTube.

Codecs and Containers - the wonderful world of video files - a fuller tour of how codecs and container formats relate to each other. It is in the CODECS.COM playlist.

Then try: drop any video into the free Codec Finder and it tells you the container and the codecs inside, right in your browser. For a full desktop report, MediaInfo does the same on Windows.

Prefer reading? Codecs vs containers: why your video file won't play covers it in writing.

Go Deeper: How Compression Really Works

How Codecs Work - David Kong. A well-made animated walk through the main tricks codecs use to shrink video without you noticing. Watch it on Vimeo.

5 THINGS: Demystifying Video Codecs - Michael Kammes. Aimed at video editors: why camera files stutter on a timeline, and why editors convert them to an edit-friendly codec first. Watch the episode.

Then try: install FFmpeg on Windows and convert a clip yourself - it is the free engine inside most video converters. To see whether your own graphics card decodes AV1 and HEVC in hardware, run the online codec checker.

Watch the Whole Playlist

All the YouTube picks, plus a few more, sit in one free playlist, Ultimate Codecs Related Guides. Press play and let it run, no sign-in needed.

New picks go into the playlist first, so follow the CODECS.COM YouTube channel if you want them as they land.

Put It to Work on Your Own Files

• A video will not play. Grab VLC Media Player, which carries its own decoders and opens almost anything.
• You see a 'codec not supported' error. Our guide to fixing codec not supported errors works through the causes in order.
• You want every player on the PC fixed at once. K-Lite Codec Pack installs the decoders system-wide in one go.
• You are uploading to YouTube. See which codec to use for YouTube uploads before you export.

Quick questions