How to Add Subtitles to a Video Free (No Watermark)

Captions make videos accessible and keep people watching with the sound off. You don’t need expensive software or a subscription to add them. Here’s how to create, edit and add subtitles to a video for free, without a watermark.

Step 1: Generate captions automatically

1. Open the free subtitle generator.
2. Drop in your video (MP4, MOV, WEBM or MKV) or audio file.
3. Choose a model: Fast for quick drafts, Balanced for most videos, Accurate for difficult audio.
4. Leave language on Auto-detect or choose it.

The speech recognition model (OpenAI’s Whisper) downloads once and runs on your own device, so your video is never uploaded. You’ll see the transcript appear as each chunk is processed.

Step 2: Edit the captions

Speech recognition is good, but not perfect. Read through and fix:

• Names, brands and jargon — use Find and replace to fix a misheard word everywhere at once.
• Numbers — check prices, dates and quantities.
• Line length — split long captions with ✂ at a natural pause, or merge short fragments.
• Timing — adjust start and end times; click ▶ to replay a caption.

The video preview shows your captions live as you edit.

Step 3a: Upload captions separately (SRT or VTT)

For YouTube, Vimeo, LinkedIn, Facebook and most video players, upload a caption file alongside your video. Viewers can turn captions on or off, and platforms can index the text.

• SRT is the most widely accepted format.
• VTT (WebVTT) is used for HTML5 video on websites.

On YouTube, go to YouTube Studio → Subtitles → Add language → Upload file and choose With timing.

Step 3b: Burn captions into the video

For Instagram Reels, TikTok, YouTube Shorts and X, burned-in captions are best: they’re part of the video and always visible.

1. Open Burn captions into the video.
2. Choose a font, size and position. For vertical video, Middle avoids the app’s buttons at the bottom.
3. Pick text, highlight and outline colours. White text with a black outline works on almost any footage.
4. Turn on Highlight words as spoken for the popular karaoke style.
5. Choose an output resolution and press Burn captions into MP4.

Rendering happens in your browser with ffmpeg and can take a few minutes for longer videos. The result has no watermark.

Caption best practices

• Two lines maximum, about 42 characters per line.
• At least one second on screen; longer for longer captions.
• Break at natural pauses, not in the middle of a phrase.
• Include meaningful sounds in brackets — [laughter], [music], [door slams] — for accessibility.
• High contrast for burned-in captions; add a background box over busy footage.
• Proofread. A misheard word in a burned-in caption can’t be fixed without re-rendering.

Why do it on your device?

Many online caption tools upload your video, keep it on their servers, limit free minutes and stamp a watermark on exports. Processing locally keeps unreleased and client videos private, with no limits or watermark. Your browser caches the model, so the next video starts faster — even offline.