Add Subtitles to a Video Permanently

Why subtitles go missing

The usual story goes like this. You watch a video in VLC with an SRT file sitting next to it, or you upload captions to YouTube, and everything looks right. Then you send the MP4 to someone, post it elsewhere or drop it into an editor, and the subtitles are gone. Nothing broke. The subtitles were being added by the player at playback, from a file or a track that only that player knew to look for, and the next app in the chain simply didn't.

Permanent subtitles skip that dependency. Once the text is rendered into the frames, it is as much a part of the video as the people in it, and any player, phone or platform that can show the picture will show the words.

Where soft subtitles get dropped

These are the hand-offs where subtitles most often disappear:

Sending through WhatsApp, Telegram or Messenger

The app sends the video alone. A sidecar SRT isn't attached, and a track inside the file is typically discarded when the app recompresses it.

Posting to Instagram, TikTok or Reels

Feeds rebuild the video from picture and sound. Any captions there come from the platform's own tools, not from a track in your file.

Moving a clip from YouTube to another site

Captions uploaded to YouTube stay on YouTube. The file you post elsewhere has none.

Importing into a video editor

Many editors bring in the picture and sound of an MKV or MP4 and skip its subtitle stream, so captions must be imported separately.

Converting or compressing

Converters often drop subtitle streams unless told to keep them, and MP4 can't hold every subtitle format an MKV can.

Playing from a USB stick on a TV

Sidecar support varies by TV model, and even supported files only load when their name matches the video exactly.

If any of these is on your video's route, a soft subtitle is a gamble.

Three ways to keep subtitles with a video

• Burn them into the picture. Survives every hand-off above. The trade-offs: viewers can't hide them, each copy carries one language, and changes mean rendering again.
• Embed a soft track in the file. Survives in players that read tracks, such as VLC and many desktop players, but is lost in chat apps and feeds. Embedding subtitles explains the tools.
• Upload the subtitle file to each platform. Works well on YouTube, Vimeo and other sites with a caption upload, but has to be repeated for every platform and never travels with the file.

Only the first is permanent in the sense most people mean when they ask. Editors call the result a hardsub, and hardcoding subtitles covers when that is and isn't the right deliverable.

Rendering them in for good

In the editor on this page, open the video (MP4, MOV, M4V, WebM or MKV) and bring the subtitles in by whichever route you have. An SRT or VTT from wherever the soft version came from goes in through Import SRT / VTT; this is usually the quickest fix for "my subtitles keep vanishing", since the text already exists. With no file, AI subtitles generate the lines from the speech, or you can type them at the playhead. Check them while the video plays, choose a style, and press Render video. When the render finishes, Download video gives you a file named after the original with -subtitled added, at the same resolution and frame rate and without a watermark. The original stays untouched on your disk.

Rendering happens in your browser on your own computer, so the video isn't uploaded for it. Without AI, nothing about the job leaves your machine; with AI subtitles, the browser uploads the audio only for transcription.

Settle these before you render

Permanent cuts both ways: whatever is wrong in the text is now permanent too. Run through this list first:

• Names, numbers and brand terms are spelled correctly, especially in AI-written lines.
• Timing feels right at normal speed; "Shift all by" fixes a file that is early or late throughout.
• No line triggers a warning you care about, such as overlaps, lines shorter than 0.8 seconds or lines too fast to read.
• The text clears whatever the destination app draws over the video; "Show safe area" helps, and subtitle safe areas explains the zones.
• The size works on a phone held at arm's length; customising subtitles covers size, weight and line width.
• You've picked the one language this copy will carry.
• You've used Export SRT, so a future correction starts from the text rather than from scratch.

If permanent subtitles are already there

Sometimes the problem is the opposite: a video arrived with permanent subtitles you don't want, perhaps in the wrong language. They can't be taken out of the picture, but "Hide subtitles already in the video" blurs a band across that part of the frame and draws your new lines on top. Everything inside the band is softened along with the old text, so it works best when the old subtitles sat in a consistent strip. Hiding burned-in subtitles covers sizing the band.

Three videos that needed to stick

For a subtitle file with no rendered video, the AI subtitle generator is the direct route, and translated subtitles gives you the file in another language.

About the subtitle editor on this page

Opens

MP4, MOV, M4V, WebM, MKV videos your browser can decode

Subtitles from

AI (from the speech, optionally translated into one of 21 languages), an SRT or VTT file, or typing them in

You download

An MP4 with the subtitles drawn into the picture at the original resolution and frame rate, plus SRT and VTT files

Cost

Editing, styling, rendering and SRT/VTT export are free, with no account and no watermark. AI subtitles cost 1 credit per minute (5-credit minimum per video); signing in with Google gives 100 free credits and accounts get 10 free credits a day

Privacy

The video never leaves your device and is rendered in your browser. Only for AI subtitles is the audio sent, over HTTPS, and it is deleted within 30 minutes of delivery

Rendering needs

Chrome or Edge 94+, Safari 16.4+, or Firefox 130+ on a computer. Editing and SRT/VTT export work in any current browser