How to prevent FFmpeg from adding 'encoder=Lavf...' metadata to MP4 output?

Question

I'm using FFmpeg to record or re-encode videos to MP4 format, and I want to completely remove all encoder metadata, especially the "encoder": "Lavf..." entry that shows up in the container-level tags.

Here's the command I'm using:

ffmpeg -i input.mp4 -c:v libx264 -profile:v baseline -level 3.1 -pix_fmt yuvj420p -x264-params bframes=0
-c:a aac -b:a 96k -ac 1
-movflags use_metadata_tags -map_metadata -1 -map_chapters -1
-metadata encoder=
-metadata creation_time="2025-06-10T13:27:00.000000Z"
-metadata major_brand=mp42 -metadata compatible_brands=isommp42
-metadata com.android.version=13
output.mp4

Even though I’ve used -metadata encoder= and stripped all metadata with -map_metadata -1, the resulting file still contains this:

"tags": {
    "creation_time": "2025-06-10T13:27:00.000000Z",
    "major_brand": "mp42",
    "compatible_brands": "isommp42",
    "com.android.version": "13",
    "encoder": "Lavf62.1.100"
}

Answer 1

If you have a really good reason for removing this important tag, try using this option (before specifying your output file output.mp4):

-fflags +bitexact -flags:v +bitexact -flags:a +bitexact

---

The explanation:

The encoder tag contains an important info for decoding your media file — it allows correctly playing back your media file without need for media player to guess which decoder(s) to use. So removing this valuable info is not a very wise thing.

For this reason, the encoder metadata is flagged with the AV_DICT_DONT_OVERWRITE flag, so it can't be deleted/overwritten directly with the -metadata option.

The above-mentioned solution is not for a regular use, but rather for developing and debugging FFmpeg.