Add sub to mp4

[Donnje]

Hi,
I have tried different software but all of them convert the video too, any solution to just add the sub?
I usually use Movavi but if I add the subs it transforms the file from 311MB to 1.18GB leaving the same video settings
thx

[ProWo]

For mp4 sub has to be converted to mov_text.
Sub/idx is incompatible with mp4.
If you want sub, then remux to mkv.

[netmask56]

If you don't want to change the size of the file just put the mp4 plus subtitle file in a MKV container using MKVToolNix. Just drag and drop the files into the main window. Quality and size In = Quality and size Out.

[pcspeak]

The subs need to be in srt format. Add a copy of ffmpeg.exe to the folder.
Subtitles-Add-Track-to-MP4 v04.cmd

@echo off
:: Video 'track name.mp4' must have matching 'track name.srt'

if not exist New\ md New
:: Add forced .srt subtitle track.
for %%a in ("*.mp4") do if exist "%%~na.srt" ffmpeg.exe -i "%%a" -sub_charenc ISO-8859-1 -i "%%~na.srt" ^
    -map 0:0 -map 0:1 -map 1:0 -disposition forced -avoid_negative_ts 1 -max_interleave_delta 0 ^
     -c:v copy -c:a copy -c:s mov_text -metadata:s:s:0 language=eng -threads 0 -y "New\%%a"

Cheers.

[Donnje]

If you don't want to change the size of the file just put the mp4 plus subtitle file in a MKV container using MKVToolNix. Just drag and drop the files into the main window. Quality and size In = Quality and size Out.

thanks, i just fixed it like this