# Editing MP4 tags seems to hang using the main window (as opposed to the left panel) **URL:** \ **Category:** Support\ **Created:** [February 5, 2021, 5:04am UTC](https://community.mp3tag.de/t/editing-mp4-tags-seems-to-hang-using-the-main-window-as-opposed-to-the-left-panel/51861 "2021-02-05T05:04:14Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Jonius](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/j/d26b3c/32.png) [@Jonius](https://community.mp3tag.de/u/Jonius)\ **Post date:** [February 5, 2021, 5:04am UTC](https://community.mp3tag.de/t/editing-mp4-tags-seems-to-hang-using-the-main-window-as-opposed-to-the-left-panel/51861/1 "2021-02-05T05:04:14Z")
I've been going through and adding Titles to my MKV footage through the main window, no problems. But I've been remuxing those MKV to MP4, and when I tried to add tags the same way, MP3Tag would freeze up, the larger the file, the worse it got. Which is weird, because I was able to add a Title tag to a 6GB MP4 very quickly using the left sidebar, but this doesn't always seem to work. Sometimes it also hangs when using the left sidebar. But at least it shows the box "Writing tag data" ![2021-02-05 14_58_06-Mp3tag v3.05 - H__OBS in 2021_SNIP](https://community.mp3tag.de/uploads/default/original/2X/a/a800434d4e0d39c5d2f11bd71b8844f0af0b2add.png) ![2021-02-05 14_58_06-Mp3tag v3.05 - H__OBS in 2021_SNIP2](https://community.mp3tag.de/uploads/default/original/2X/9/97f3d8764cdf9c1ac6406572eb5c9d9acecf27ad.png) ---
**Author:** ![ohrenkino](https://community.mp3tag.de/user_avatar/community.mp3tag.de/ohrenkino/32/4843_2.png) [@ohrenkino](https://community.mp3tag.de/u/ohrenkino)\ **Post date:** [February 5, 2021, 5:26am UTC](https://community.mp3tag.de/t/editing-mp4-tags-seems-to-hang-using-the-main-window-as-opposed-to-the-left-panel/51861/2 "2021-02-05T05:26:49Z")
If the padding for tags is not big enough then the file has to be re-written. Re-writing GBs may take some time. As there have been a number of changes in respect to MP4 files: which version do you use? The current version is 3.05. ---
**Author:** ![Jonius](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/j/d26b3c/32.png) [@Jonius](https://community.mp3tag.de/u/Jonius)\ **Post date:** [February 5, 2021, 5:32am UTC](https://community.mp3tag.de/t/editing-mp4-tags-seems-to-hang-using-the-main-window-as-opposed-to-the-left-panel/51861/3 "2021-02-05T05:32:21Z")
I'm using 3.05 I also mention this because I tried the same files in MetaX and they tagged very quickly, as expected. I think VLC does it, but it takes too many clicks to be useful. I'd rather use MP3Tag if possible, as I can just open each file, and go down the list adding each tag. ---
**Author:** ![phw](https://community.mp3tag.de/user_avatar/community.mp3tag.de/phw/32/11831_2.png) [@phw](https://community.mp3tag.de/u/phw)\ **Post date:** [February 5, 2021, 6:08am UTC](https://community.mp3tag.de/t/editing-mp4-tags-seems-to-hang-using-the-main-window-as-opposed-to-the-left-panel/51861/4 "2021-02-05T06:08:29Z")
> [@Jonius](#): > > I also mention this because I tried the same files in MetaX and they tagged very quickly, Did you try this _after_ you had already tagged them with MP3Tag? If yes this would be expected and indicates what Ohrenkino said. You would also find MP3Tag being quicker when saving a second time unless you add a lot of additional tag data ---
**Author:** ![Jonius](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/j/d26b3c/32.png) [@Jonius](https://community.mp3tag.de/u/Jonius)\ **Post date:** [February 5, 2021, 7:00am UTC](https://community.mp3tag.de/t/editing-mp4-tags-seems-to-hang-using-the-main-window-as-opposed-to-the-left-panel/51861/5 "2021-02-05T07:00:45Z")
So, it's hanging the first time, if I tag it with MP3Tag. Afterwards it seems to be fast, but at that point I'm moving on to the next file. I'm noticing MP3Tag creating .tmp files while trying to apply the tag. Even if I just click on a tag and don't change the name, it will try to rewrite the tag. ---
**Author:** ![system](https://community.mp3tag.de/uploads/default/original/2X/c/ce7035d426cb755a7916793326d23b465222a407.png) [@system](https://community.mp3tag.de/u/system)\ **Post date:** [February 9, 2026, 12:29pm UTC](https://community.mp3tag.de/t/editing-mp4-tags-seems-to-hang-using-the-main-window-as-opposed-to-the-left-panel/51861/6 "2026-02-09T12:29:03Z")