Q: "What is the easiest way to add a hard subtitle to an mp4 video?" - From Quora

MP4 is one of the most popular formats. Some people loving to make videos often choose MP4 as the output format. Have you ever met the situation that your favorite MP4 movie has no subtitles? That may make you mad. Because subtitles can help people quickly know the contents of the videos. They are very important to some people with poor hearing or those who watch videos with a foreign language. Then, how to add subtitles (.SRT files) to MP4 Video video by yourself? You can find the answer in this article, which lists 3 video editors.

Part 1. Add Subtitles to MP4 by Joyoshare Video Joiner

Joyoshare Video Joiner is a professional tool to combine SRT files to MP4 video. Except for that, Joyoshare also allows you to add subtitles to videos with other formats, like MOV, M4V, AVI, MPG, etc. Before merging SRT and MP4, you can cut the unwanted parts of the MP4 files. Also, if necessary, you can edit the video, like rotate or crop the screen picture, adjust the brightness, contrast, saturation or hue, add some video effects and frames, insert background music to videos and watermark, and so on. After adding SRT files to MP4, then you can export it at 60X faster speed. Of course, you can also convert the MP4 file to any other popular video formats or extract the audios from it.

What makes Joyoshare outstanding from multiple subtitle editors:

Add subtitles to MP4

Support various subtitle formats, like SRT, ASS, SSA, IDX, SMI

Use Joyoshare without any skills

Offer 5 opportunities to use it before registering

Without the company logo in the trial version

Steps to merge SRT and MP4 files:

Step 1Import MP4 video to Joyoshare

After downloading and installing Joyoshare Video Joiner, run it. Then you can add MP4 files to Joyoshare with 2 ways: Drag and drop MP4 video to the left screen; Select from the local folder.
add mp4video to the program

Step 2Select one mode and the output format

There are two modes in Joyoshare: High-Speed mode & Encoding mode. Each has multiple formats. Here we choose the latter and pick MP4 as the output format.
choose merging mode and output format

Step 3Trim needless parts of the MP4 file

Joyoshare Video Joiner has an inbuilt video cutter. You can easily cut some commercials or footage.
cut mp4

Step 4Edit MP4 files before adding subtitles to MP4

In this step, you can edit MP4 as you like. You can adjust the rotation of the video, crop the video, and apply some video effects.
edit mp4

Step 5Add SRT files to MP4

Click the File button and select the one SRT file. And then preview the MP4 video with subtitles.
add subtitles to mp4

Step 6Start to export MP4 with subtitles

Click the Convert button on the left bottom, then your MP4 inserted subtitles will export at 60X faster speed.
export mp4 with subtitles

Note: You can use Joyoshare Video Joiner to combine SRT files and MP4 on both Windows and Mac computers. But if you want to do that in the Linux system, then you should try HandBrake.