Container versus codec
MDN defines a media container as a file format that encapsulates one or more media streams, such as audio or video, along with metadata, so they can be stored and played back together. [1] A file format is defined by several parts together: the codecs, the container and optional extras such as subtitles. [1]
Think of the container as the box and the codec as how each item inside was packed. An MP4 box can hold H.264, AV1 or VP9 video with AAC, FLAC, MP3 or Opus audio. [1] A player needs to understand both: it can open the box and still fail to unpack a codec it does not support. [2]
That is why renaming a file from .mkv to .mp4 does not convert it. The extension is only a label; the internal structure stays the same. Changing containers properly means remuxing, and changing codecs means re-encoding.
The four containers creators meet
MP4 is defined in the MPEG-4 standard and derived from the ISO base media file format, which comes from Apple QuickTime format. MDN calls it broadly supported. [1] YouTube recommends MP4 for uploads, with no edit lists and the moov atom at the front of the file (Fast Start). [4]
MOV is Apple QuickTime container. MDN notes it served as the basis for MP4 but the two are not quite interchangeable, and that browsers generally do not play QuickTime files directly. [1] It remains common for camera and editing workflows, especially with ProRes. OBS lists ProRes as supported only in MOV and MKV. [3]
MKV (Matroska) accepts almost any codec. The OBS guide recommends MKV for most use cases because it supports every codec combination OBS offers and stays playable and recoverable after a power loss, but rates its editing support as poor. [3] WebM is based on Matroska and designed for the web; compliant players must support VP8 and VP9 video and Vorbis and Opus audio, and AV1 is also supported. [1]
| Container | Extension | Typical video codecs | Strength | Weakness |
|---|---|---|---|---|
| MP4 | .mp4 | H.264, HEVC, AV1 [1][3] | Broadly supported; YouTube recommended [1][4] | Interrupted recordings may be unrecoverable [3] |
| MOV | .mov | H.264, HEVC, ProRes [3] | Strong in Mac and pro editing workflows [3] | Browsers generally do not play it [1] |
| MKV | .mkv | Any OBS codec [3] | Survives crashes and power loss [3] | Poor editing support [3] |
| WebM | .webm | VP8, VP9, AV1 [1] | Open formats; built for the web [1] | Less common in editors and camera workflows |
Why recorders like MKV and editors like MP4
A regular MP4 or MOV must be finalised when recording stops. OBS says that if the recording is interrupted, such a file may be unrecoverable, and advises against recording to it directly. [3] MKV is written so that everything up to the crash stays playable. [3]
OBS now offers middle grounds. Hybrid MP4 (the default on Windows and Linux) and Hybrid MOV (the default on macOS) combine fragmented and regular structure for crash resilience with excellent editing support. Fragmented MP4 and MOV are also built for crash resilience, with good editing support, though some editors need a remux when the audio is lossless or uncompressed. [3]
So the sensible split is: record in a crash-resistant container, edit and deliver in MP4 or MOV.
When MKV or WebM needs rewrapping
Rewrap when an editor will not import a file, imports it without audio, or imports it with broken timing. OBS notes that MKV may require remuxing for use in editing software. [3] A remux copies the existing streams into a new container without re-encoding them.
Read import lists literally. Filmora, for example, lists Matroska import as .mkv encoded with MPEG-4 or MJPEG, while it lists AV1 in .mp4 and .webm separately. [5] An H.264 MKV from OBS is therefore not something that list promises to open; remuxing it to MP4 is the safer move.
Remuxing only works when the target container supports the codecs inside. OBS lists which codecs fit which container: H.264 fits MP4, MOV and MKV; HEVC fits MP4, MOV and MKV; AV1 fits MP4 and MKV; ProRes fits only MOV and MKV. [3] A ProRes MKV should be rewrapped to MOV, not MP4. When the codec itself is the problem, you need a re-encode, not a remux.
Compatibility table: recorders, editors and upload targets
This table lists only what each official source states. Where a target is not listed for a container, that means the source does not mention it, not that it is guaranteed to fail.
| Tool or platform | MP4 | MOV | MKV | WebM |
|---|---|---|---|---|
| OBS Studio (records) | Yes, plus Hybrid and Fragmented [3] | Yes, plus Hybrid and Fragmented [3] | Yes, default for resilience [3] | Not listed [3] |
| Filmora (imports) | Yes [5] | Listed with MPEG-4 or MJPEG [5] | Listed with MPEG-4 or MJPEG [5] | Yes (AV1, HTML5) [5] |
| Filmora (exports) | Yes, incl. HEVC and AV1 [5] | Yes, incl. ProRes at 8K [5] | Yes [5] | Yes [5] |
| YouTube | Recommended [4] | Not stated in recommendations [4] | Not stated in recommendations [4] | Not stated in recommendations [4] |
| Yes [6] | Yes [6] | Yes [6] | Yes [6] | |
| TikTok ads | Yes [7] | Yes [7] | Not listed [7] | Not listed [7] |
| Facebook Feed ads | Yes [8] | Yes [8] | Not listed [8] | Not listed [8] |
Checklist for containers in a creator workflow
Most container trouble disappears if you choose deliberately at each stage instead of accepting defaults.
- Record in MKV, Hybrid MP4/MOV or Fragmented MP4/MOV so a crash does not cost the take. [3]
- Remux MKV to MP4, or to MOV for ProRes, before importing into an editor that does not list it. [3][5]
- Never rename an extension to convert a file; remux or re-encode instead.
- Deliver MP4 with H.264 unless the destination asks for something else. [1][4]
- For YouTube, export MP4 with Fast Start and without edit lists. [4]
- For Meta ads, use MP4 or MOV without edit lists or special container boxes. [8]
- Keep the original recording until the remuxed or exported file has been checked end to end.
Questions before you decide
Is MP4 a codec?
No. MP4 is a container that holds video, audio and metadata streams. The codec inside an MP4 might be H.264, HEVC or AV1, and a player must support both the container and the codec to play the file.
Why does OBS recommend recording to MKV?
OBS calls MKV the recommended container for most use cases because it supports every codec combination OBS offers and stays playable and recoverable after a power loss, whereas a regular MP4 or MOV must be finalised and may be unrecoverable if recording is interrupted. OBS also offers Hybrid and Fragmented MP4 and MOV as crash-resistant options.
Can I upload MKV or WebM to LinkedIn?
LinkedIn Help lists MP4, MOV, AVI, WEBM, MKV and several other formats as supported on desktop, iOS and Android, but notes that a ProRes file may upload and then fail to process, so test unusual codecs first.
Does remuxing reduce quality?
Remuxing moves the existing streams into a new container without compressing them again, so the picture and sound stay as they were. It only works when the new container supports the codecs inside; otherwise you need to re-encode.
Sources & verification
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- MDN Web Docs: Media container formats (file types) Accessed 30 Oct 2026
- MDN Web Docs: Web video codec guide Accessed 30 Oct 2026
- OBS Studio Knowledge Base: Audio/Video Formats Guide Accessed 30 Oct 2026
- YouTube Help: YouTube recommended upload encoding settings Accessed 30 Oct 2026
- Wondershare Filmora: Tech specs (Windows) Accessed 30 Oct 2026
- LinkedIn Help: Video sharing troubleshooting Accessed 30 Oct 2026
- TikTok Ads Manager Help: Video ads specifications Accessed 30 Oct 2026
- Meta Ads Guide: Facebook Feed video specs Accessed 30 Oct 2026
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