Complete Guide: How to Add Subtitles (.srt/.ass) to MP4, MKV, MOV, and AVI?

Part 1: Subtitle Formats and How You Should Embed Subtitles into Your Videos

In works such as movies, TV shows, video games, and music videos, subtitles are always displayed as dialogue text at the bottom or top of the video. Most subtitles consist only of text characters because text is the easiest data type to store and compress. Common subtitle formats include SRT, ASS, SSA, IDX, and SUB, among which SRT and ASS are probably the most popular.

Hard subtitles mean they become a permanent part of the video and cannot be turned off. You can only hardcode one subtitle file. But the good news is that all formats support hard-coded subtitles. In other words, you can hardcode subtitles into any video you want.

Soft subtitles allow you to toggle subtitles on or off. Only MKV, MP4, and MOV formats support soft subtitles, and you can attach multiple subtitles into these videos to choose the viewing language at will.

Now you should have a basic idea of the type of subtitles you want. Let's move on to learn in detail how to add subtitles to MP4, MKV, MOV, and AVI videos.

Part 2: Detailed Guides on How to Add Subtitles to Your Videos

Download Recommended Subtitle Tool: WonderFox HD Video Converter Factory Pro

To add external subtitles to videos, a video subtitle joiner is essential.

On Windows, WonderFox HD Video Converter Factory Pro is the perfect subtitle tool that can help you easily add SRT and SSA subtitles to any video. It supports both hardcoding subtitles and attaching soft subtitles to your movies. Meanwhile, it doesn't require converting (re-encoding) your video, so it will maintain the original video quality and offer fast processing speed.

Let's download the software now and follow the methods below:

Bonus Tip: How to Load Subtitles Directly in MP4, MKV, MOV, and AVI?

Some video players, such as VLC, PotPlayer, and GOM Player, can auto-load external subtitles when playing videos, so you don't really need to manually add soft subtitles to your MP4 or other videos. Here are the general steps to make your subtitles show in the video:

That said, this method is not guaranteed to work for every case, especially if your media player does not have a subtitle option. It's still recommended to embed subtitles into your video permanently for error-free playback.

Extended Reading: Top 5 Subtitle Sites to Find Your Wanted Subtitles

If you need to find external subtitle files to add subtitles to your videos, here are 5 of the most popular subtitle websites where you can download SRT format subtitles for free.

1. Subscene (Shutdown)

Website: http://subscene.com/

Subscene is an international subtitle site for films and TV series. Just type the right name and title, you can get many search results with multiple languages subtitles for mp4. Subtitle filter is more helpful for your preferred language.

2. OpenSubtitles

Website: http://www.opensubtitles.org/en/search

OpenSubtitles is an open multi-language subtitle database. It is one of the best and certainly the most visited subtitle website. Advanced search enables you to find what you need much faster.

3. Addic7ed

Website: http://www.addic7ed.com/

Addic7ed is one of the popular sites where TV shows and movies subtitles can be downloaded for free. They aim to provide fast and quality subtitles for your favorite TV shows and movies. It's currently down for maintenance, please stay tuned.

4. Moviesubtitles

Website: http://www.moviesubtitles.org/

On Moviesubtitles, you can find subtitles for the most popular movies and TV films. Subtitles are available in multiple languages. All subtitles here are packed with WinZip.

5. YIFY Subtitles

Website: https://yts-subs.com/

YIFY Subtitles aims to help you find and download the subtitles you need quickly, without having to avoid popups and struggling hard to find the download button among ads. It's also one of the largest and well-known sites with high reputation.

Hope you have successfully solved the subtitle problem and know how to use SRT and ASS files with MP4, MKV, MOV, and AVI after reading this tutorial.

FAQ

1. Why are subtitles important?

The history of subtitles can be traced back to silent films, when words were used to describe the story, which formed an early form of subtitles. Today, subtitles are increasingly important for videos because they not only help hard-of-hearing people understand the content of the video, but also build a bridge between non-native speakers and native speakers, thus reducing communication costs.

2. What's the difference between soft and hard subtitles?

Soft subtitles are added as a separate track within the video file, allowing you to turn them on or off as needed. Hard-coded (or burned-in) subtitles are permanently embedded into the video, becoming a part of the image itself.

3. How do I permanently add subtitles to a video?

You need to hardcode subtitles to videos so the subtitles are burned into the video permanently. You can use the subtitle hardcoding tool WonderFox HD Video Converter Factory Pro to do it easily. Check out the detailed steps >>

4. How do I add SRT files to my MP4?

You can use the program introduced in this article to insert SRT files into MP4 videos effectively. Detailed steps are outlined above.

5. Can I add multiple subtitles to a video?

Yes, MKV, MP4, and MOV support multiple subtitle tracks, and you can add multiple external subtitle tracks to these format videos with the steps outlined above.

6. How can I add subtitles to MP4 without re-encoding?

You can add subtitles to MP4 without re-encoding by inserting soft subtitles.

7. Does adding subtitles to a video affect the video quality?

Adding soft subtitles will not re-encode or affect the video quality in any way since subtitles are just an additional text track synced to the video. However, hard-coding subtitles will re-encode the video, slightly altering the quality during the encoding process.