Runs on your device
Add Subtitles to Video
Combine a local MP4 video with SRT or VTT subtitles, preview the caption style, and export a video with permanent subtitles.
Choose a video and subtitles to get started.
Use a video up to 100 MB and 5 minutes. Export resolution is capped at 1080p.
MP4 support depends on your browser’s video decoder and H.264 encoder. Audio, when present, must be AAC in this first version.
Export uses your device’s memory and processing power. Keep this tab open and start with a short video.
Your video and subtitles stay on this device. Preview and export run locally in your browser.
Video preview
Play the video to check caption text, timing, and placement before exporting.
Choose a video and subtitles to preview the result.
Related subtitle tools
How to add subtitles to a video
- Choose a compatible MP4 video and load matching SRT or VTT subtitles, or paste your timed subtitles.
- Choose caption colors, size, background, and position. Play the preview and select an output resolution.
- Export locally, keep the tab open during processing, and download the captioned MP4 when it is ready.
Frequently asked questions
Are my video or subtitle files uploaded?
No. The selected files are processed in your browser on your device. An internet connection is needed to load the app.
Can viewers turn these subtitles off?
No. The subtitles are burned into the video image and remain visible during playback. Keep your original video and subtitle files if you also need switchable captions.
Will video or audio quality change?
The video is re-encoded, so its quality and file size can change. Smaller output resolutions reduce detail. The supported AAC audio track is kept; unsupported audio is reported instead of silently removed.
Export an MP4 video with permanent subtitles
Add readable captions to a local video without uploading the source files. Use your existing SRT or WebVTT track and review its appearance before exporting.
Burn SRT and VTT into video
Turn timed subtitle cues into visible text in the exported video image. Permanent captions work wherever the MP4 is played, even when a player has no subtitle-file support.
Style captions and check the preview
Adjust text size, colors, background opacity, bold text, and vertical position. Preview the captions alongside the video to check readability and timing.
Local export for compatible short videos
Export takes place on your device with supported browser codecs. Short videos and modest output resolutions help keep processing and memory use manageable.