# Cannot edit large MP4 files (\> 2 GiB)

**URL:** <https://community.mp3tag.de/t/cannot-edit-large-mp4-files-2-gib/18286>\
**Category:** Support\
**Created:** [October 3, 2016, 8:08am UTC](https://community.mp3tag.de/t/cannot-edit-large-mp4-files-2-gib/18286 "2016-10-03T08:08:09Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Technologov](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/t/ee7513/32.png) [@Technologov](https://community.mp3tag.de/u/Technologov)\
**Post date:** [October 3, 2016, 8:08am UTC](https://community.mp3tag.de/t/cannot-edit-large-mp4-files-2-gib/18286/1 "2016-10-03T08:08:09Z")

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Hello.

I have a bunch of large MP4 (MPEG-4-AVC) files between 4 GB and 25 GB, and this program never writes metadata to those files.

After re-reading my files from disk again, I find out that nothing was saved. It seems to work with small MP4 files, under 2 GB.

Can you check out why ?

v2.78 on Win7 x64.

-Alexey

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**Author:** ![MP3Freak\_Peter](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/m/c68b51/32.png) [@MP3Freak\_Peter](https://community.mp3tag.de/u/MP3Freak_Peter)\
**Post date:** [October 3, 2016, 10:25am UTC](https://community.mp3tag.de/t/cannot-edit-large-mp4-files-2-gib/18286/2 "2016-10-03T10:25:18Z")

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Depending on tag type, file needs to be rewritten when changing tags.

Your problem sounds like mp3tag would read whole file in memory for rewriting instead of reading/writing block by block... but I can not believe that...

**edit:**  
Check memory usage when mp3tag is processing an large single file.  
Can you post a sceenshot of taskmanager or sysinternal process monitor?

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**Author:** ![Technologov](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/t/ee7513/32.png) [@Technologov](https://community.mp3tag.de/u/Technologov)\
**Post date:** [October 4, 2016, 7:59pm UTC](https://community.mp3tag.de/t/cannot-edit-large-mp4-files-2-gib/18286/3 "2016-10-04T19:59:13Z")

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> [@MP3Freak\_Peter](#):
>
> Depending on tag type, file needs to be rewritten when changing tags.
> 
> Your problem sounds like mp3tag would read whole file in memory for rewriting instead of reading/writing block by block... but I can not believe that...
> 
> **edit:**  
> Check memory usage when mp3tag is processing an large single file.  
> Can you post a sceenshot of taskmanager or sysinternal process monitor?

Well, this happens.  
Sometimes it takes a long time - 3% CPU usage. (few minutes) Sometimes this is instant.  
But NOTHING gets saved Just try it.

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**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, 12:26pm UTC](https://community.mp3tag.de/t/cannot-edit-large-mp4-files-2-gib/18286/4 "2026-02-09T12:26:27Z")

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